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Zhang H, Guo Y, Chen Y, Xie B, Lai S, Liu H, Hou M, Ma L, Chen X, Wong CP. Nanorobot Swarms Made with Laser-Induced Graphene@Fe 3O 4 Nanoparticles with Controllable Morphology for Targeted Drug Delivery. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 39376076 DOI: 10.1021/acsami.4c10355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/09/2024]
Abstract
Magnetic nanorobot swarms can mimic group behaviors in nature and can be flexibly controlled by programmable magnetic fields, thereby having great potential in various applications. This paper presents a novel approach for the rapid and large-scale processing of laser-induced graphene (LIG) @Fe3O4-based-nanorobot swarms utilizing one-step UV laser processing technology. The swarm is capable of forming a variety of reversible morphologies under the magnetic field, including vortex-like and strip-like, as well as the interconversion of these, demonstrating high levels of controllability and flexibility. Moreover, the maximum forward motion speed of the nanorobot swarm is up to 2165 μm/s, and the drug loading and release ability of such a nanorobot swarm is enhanced about 50 times due to the presence of graphene, enabling the nanorobot swarm to show rapid and precise targeted drug delivery. Importantly, by controllable morphology transformation to conform to the complicated requirements for the magnetic field, the drug-loaded swarm can smoothly pass through a width-varying zigzag channel while maintaining 96% of the initial drug-loading, demonstrating that LIG @Fe3O4 NPs-based nanorobot swarm can provide effective and controllable targeted drug delivery in complex passages.
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Affiliation(s)
- Hao Zhang
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Yuanhui Guo
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Yun Chen
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Bin Xie
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Shengbao Lai
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Huilong Liu
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Maoxiang Hou
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Li Ma
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xin Chen
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Ching-Ping Wong
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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2
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Shvetsov S, Orlova T, Hayrapetyan A, Vasil'ev A, Rafayelyan M. Light-controllable liquid crystal platform for microparticle oscillations and transport. SOFT MATTER 2024; 20:6920-6928. [PMID: 39161989 DOI: 10.1039/d4sm00771a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/21/2024]
Abstract
Liquid crystal colloids manifest complex motion caused by external stimuli, but tunable and addressable control of microsized objects remains a challenge. This study aims to demonstrate light-driven trapping, transport, and sustained periodic motions of microparticles by employing liquid crystal films as a light-controllable colloidal platform. The diverse motions of microscopic particles result from Marangoni convection coupled with elastic deformations in free-surface liquid crystal films subjected to light beam heating. The specific mode of particle motion, including damped and sustained oscillations, also combined with sustained rotation, is defined by the liquid crystal chirality, particle surface treatment, film thickness, and the power of the tightly focused light beam. The results reveal that free-surface liquid crystals provide a unique platform for the indirect optical manipulation of microscopic objects, paving the way for novel applications in microfluidic tools, particle sorting and transport, micropatterning, and various micromachines.
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Affiliation(s)
- Sergey Shvetsov
- Institute of Physics, Yerevan State University, 1 Alex Manoogian st., Yerevan 0025, Armenia.
| | - Tetiana Orlova
- Institute of Physics, Yerevan State University, 1 Alex Manoogian st., Yerevan 0025, Armenia.
- Infochemistry Scientific Center, ITMO University, 9 Lomonosova st., Saint-Petersburg 191002, Russia
| | - Aleksandr Hayrapetyan
- Institute of Physics, Yerevan State University, 1 Alex Manoogian st., Yerevan 0025, Armenia.
| | - Alexey Vasil'ev
- Innovation Center for Nanoscience and Technologies, A.B. Nalbandyan Institute of Chemical Physics NAS RA, 5/2 P. Sevak st., Yerevan 0014, Armenia
| | - Mushegh Rafayelyan
- Institute of Physics, Yerevan State University, 1 Alex Manoogian st., Yerevan 0025, Armenia.
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3
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Čopar S, Kos Ž. Many-defect solutions in planar nematics: interactions, spiral textures and boundary conditions. SOFT MATTER 2024; 20:6894-6906. [PMID: 39150404 DOI: 10.1039/d4sm00586d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
From incompressible flows to electrostatics, harmonic functions can provide solutions to many two-dimensional problems and, similarly, the director field of a planar nematic can be determined using complex analysis. We derive a closed-form solution for a quasi-steady state director field induced by an arbitrarily large set of point defects and circular inclusions with or without fixed rotational degrees of freedom, and compute the forces and torques acting on each defect or inclusion. We show that a complete solution must include two types of singularities, generating a defect winding number and its spiral texture, which have a direct effect on defect equilibrium textures and their dynamics. The solution accounts for discrete degeneracy of topologically distinct free energy minima which can be obtained by defect braiding. The derived formalism can be readily applied to equilibrium and slowly evolving nematic textures for active or passive fluids with multiple defects present within the orientational order.
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Affiliation(s)
- Simon Čopar
- Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia.
| | - Žiga Kos
- Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia.
- Department of Condensed Matter Physics, Jožef Stefan Institute, Ljubljana, Slovenia
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Higashi-Hiroshima, Japan
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4
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Ren Z, Xin C, Liang K, Wang H, Wang D, Xu L, Hu Y, Li J, Chu J, Wu D. Femtosecond laser writing of ant-inspired reconfigurable microbot collectives. Nat Commun 2024; 15:7253. [PMID: 39179567 PMCID: PMC11343760 DOI: 10.1038/s41467-024-51567-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 08/12/2024] [Indexed: 08/26/2024] Open
Abstract
Microbot collectives can cooperate to accomplish complex tasks that are difficult for a single individual. However, various force-induced microbot collectives maintained by weak magnetic, light, and electric fields still face challenges such as unstable connections, the need for a continuous external stimuli source, and imprecise individual control. Here, we construct magnetic and light-driven ant microbot collectives capable of reconfiguring multiple assembled architectures with robustness. This methodology utilizes a flexible two-photon polymerization strategy to fabricate microbots consisting of magnetic photoresist, hydrogel, and metal nanoparticles. Under the cooperation of magnetic and light fields, the microbots can reversibly and selectively assemble (e.g., 90° assembly and 180° assembly) into various morphologies. Moreover, we demonstrate the ability of assembled microbots to cross a one-body-length gap and their adaptive capability to move through a constriction and transport microcargo. Our strategy will broaden the abilities of clustered microbots, including gap traversal, micro-object manipulation, and drug delivery.
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Affiliation(s)
- Zhongguo Ren
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Chen Xin
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China.
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong, 999077, China.
| | - Kaiwen Liang
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Heming Wang
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Dawei Wang
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Liqun Xu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Yanlei Hu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Jiawen Li
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Jiaru Chu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Dong Wu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China.
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Senyuk B, Wu JS, Smalyukh II. Out-of-equilibrium interactions and collective locomotion of colloidal spheres with squirming of nematoelastic multipoles. Proc Natl Acad Sci U S A 2024; 121:e2322710121. [PMID: 38652740 PMCID: PMC11067049 DOI: 10.1073/pnas.2322710121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/14/2024] [Indexed: 04/25/2024] Open
Abstract
Many living and artificial systems show similar emergent behavior and collective motions on different scales, starting from swarms of bacteria to synthetic active particles, herds of mammals, and crowds of people. What all these systems often have in common is that new collective properties like flocking emerge from interactions between individual self-propelled or driven units. Such systems are naturally out-of-equilibrium and propel at the expense of consumed energy. Mimicking nature by making self-propelled or externally driven particles and studying their individual and collective motility may allow for deeper understanding of physical underpinnings behind collective motion of large groups of interacting objects or beings. Here, using a soft matter system of colloids immersed into a liquid crystal, we show that resulting so-called nematoelastic multipoles can be set into a bidirectional locomotion by external oscillating electric fields. Out-of-equilibrium elastic interactions between such colloidal objects lead to collective flock-like behaviors emerging from time-varying elasticity-mediated interactions between externally driven propelling particles. Repulsive elastic interactions in the equilibrium state can be turned into attractive interactions in the out-of-equilibrium state under applied external electric fields. We probe this behavior at different number densities of colloidal particles and show that particles in dense dispersions collectively select the same direction of a coherent motion due to elastic interactions between near neighbors. In our experimentally implemented design, their motion is highly ordered and without clustering or jamming often present in other colloidal transport systems, which is promising for technological and fundamental-science applications, like nano-cargo transport, out-of-equilibrium assembly, and microrobotics.
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Affiliation(s)
- Bohdan Senyuk
- Department of Physics, University of Colorado, Boulder, CO80309
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM), Hiroshima University, Higashi-Hiroshima, Hiroshima739-0046, Japan
| | - Jin-Sheng Wu
- Department of Physics, University of Colorado, Boulder, CO80309
| | - Ivan I. Smalyukh
- Department of Physics, University of Colorado, Boulder, CO80309
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM), Hiroshima University, Higashi-Hiroshima, Hiroshima739-0046, Japan
- Materials Science and Engineering Program, University of Colorado, Boulder, CO80309
- Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado, Boulder, CO80309
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6
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Wang Y, Chen H, Xie L, Liu J, Zhang L, Yu J. Swarm Autonomy: From Agent Functionalization to Machine Intelligence. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2312956. [PMID: 38653192 DOI: 10.1002/adma.202312956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/17/2024] [Indexed: 04/25/2024]
Abstract
Swarm behaviors are common in nature, where individual organisms collaborate via perception, communication, and adaptation. Emulating these dynamics, large groups of active agents can self-organize through localized interactions, giving rise to complex swarm behaviors, which exhibit potential for applications across various domains. This review presents a comprehensive summary and perspective of synthetic swarms, to bridge the gap between the microscale individual agents and potential applications of synthetic swarms. It is begun by examining active agents, the fundamental units of synthetic swarms, to understand the origins of their motility and functionality in the presence of external stimuli. Then inter-agent communications and agent-environment communications that contribute to the swarm generation are summarized. Furthermore, the swarm behaviors reported to date and the emergence of machine intelligence within these behaviors are reviewed. Eventually, the applications enabled by distinct synthetic swarms are summarized. By discussing the emergent machine intelligence in swarm behaviors, insights are offered into the design and deployment of autonomous synthetic swarms for real-world applications.
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Affiliation(s)
- Yibin Wang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China
- Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen, 518172, China
| | - Hui Chen
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China
- Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen, 518172, China
| | - Leiming Xie
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China
- Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen, 518172, China
| | - Jinbo Liu
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China
- Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen, 518172, China
| | - Li Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong, 999077, China
| | - Jiangfan Yu
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China
- Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen, 518172, China
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7
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Feng J, Zou J, Li X, Du X. Biomimetic submicromotor with NIR light triggered motion and cargo release inspired by cuttlefish. NANOSCALE 2023; 15:16687-16696. [PMID: 37819394 DOI: 10.1039/d3nr03739h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Biomimetic design is very helpful and significant for the smart construction of micro/nanomotors with artificial intelligence. In this work, inspired by cuttlefish, who can rapidly eject poisonous ink and are also capable of fast movement to escape, we designed and fabricated a biomimetic submicromotor with the ability of simultaneous quick movement and a temperature threshold caused explosive cargo release triggered by near infra-red (NIR) light irradiation, which was approximately equivalent to the action of cuttlefish when encountering a predator. The yolk@shell structured polydopamine@mesoporous silica (PDA@MS60) with immovable and asymmetric yolk distribution was employed as a platform, and this was followed by the simultaneous encapsulation of phase change materials (PCM) and cargo molecules. The NIR light irradiation could not only propel the direct motion of the submicromotor, but also caused the explosive release of the cargo loaded in the submicromotor when the temperature exceeded the melting point of the PCM.
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Affiliation(s)
- Jiameng Feng
- Beijing Key Laboratory for Bioengineering and Sensing Technology, Department of Chemistry & Biological Engineering, University of Science & Technology Beijing, Beijing 100083, China.
| | - Junjie Zou
- Department of Vascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
| | - Xiaoyu Li
- National Engineering Research Center of Green Recycling for Strategic Metal Resources, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academic of Sciences, University of Chinese Academic of Sciences, Beijing 100190, China
| | - Xin Du
- Beijing Key Laboratory for Bioengineering and Sensing Technology, Department of Chemistry & Biological Engineering, University of Science & Technology Beijing, Beijing 100083, China.
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8
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Junot G, De Corato M, Tierno P. Large Scale Zigzag Pattern Emerging from Circulating Active Shakers. PHYSICAL REVIEW LETTERS 2023; 131:068301. [PMID: 37625048 DOI: 10.1103/physrevlett.131.068301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/21/2023] [Indexed: 08/27/2023]
Abstract
We report the emergence of large zigzag bands in a population of reversibly actuated magnetic rotors that behave as active shakers, namely squirmers that shake the fluid around them without moving. The shakers collectively organize into dynamic structures displaying self-similar growth and generate topological defects in the form of cusps that connect vortices of rolling particles with alternating chirality. By combining experimental analysis with particle-based simulation, we show that the special flow field created by the shakers is the only ingredient needed to reproduce the observed spatiotemporal pattern. We unveil a self-organization scenario in a collection of driven particles in a viscoelastic medium emerging from the reduced particle degrees of freedom, as here the frozen orientational motion of the shakers.
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Affiliation(s)
- Gaspard Junot
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Marco De Corato
- Aragon Institute of Engineering Research (I3A), University of Zaragoza, 50018 Zaragoza, Spain
| | - Pietro Tierno
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
- Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain
- Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, 08028 Barcelona, Spain
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9
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Wang Q, Jin D. Active Micro/Nanoparticles in Colloidal Microswarms. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1687. [PMID: 37242103 PMCID: PMC10220621 DOI: 10.3390/nano13101687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 05/18/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
Colloidal microswarms have attracted increasing attention in the last decade due to their unique capabilities in various complex tasks. Thousands or even millions of tiny active agents are gathered with distinctive features and emerging behaviors, demonstrating fascinating equilibrium and non-equilibrium collective states. In recent studies, with the development of materials design, remote control strategies, and the understanding of pair interactions between building blocks, microswarms have shown advantages in manipulation and targeted delivery tasks with high adaptability and on-demand pattern transformation. This review focuses on the recent progress in active micro/nanoparticles (MNPs) in colloidal microswarms under the input of an external field, including the response of MNPs to external fields, MNP-MNP interactions, and MNP-environment interactions. A fundamental understanding of how building blocks behave in a collective system provides the foundation for designing microswarm systems with autonomy and intelligence, aiming for practical application in diverse environments. It is envisioned that colloidal microswarms will significantly impact active delivery and manipulation applications on small scales.
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Affiliation(s)
- Qianqian Wang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211000, China
| | - Dongdong Jin
- School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518000, China
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10
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Ji F, Wu Y, Pumera M, Zhang L. Collective Behaviors of Active Matter Learning from Natural Taxes Across Scales. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203959. [PMID: 35986637 DOI: 10.1002/adma.202203959] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/23/2022] [Indexed: 06/15/2023]
Abstract
Taxis orientation is common in microorganisms, and it provides feasible strategies to operate active colloids as small-scale robots. Collective taxes involve numerous units that collectively perform taxis motion, whereby the collective cooperation between individuals enables the group to perform efficiently, adaptively, and robustly. Hence, analyzing and designing collectives is crucial for developing and advancing microswarm toward practical or clinical applications. In this review, natural taxis behaviors are categorized and synthetic microrobotic collectives are discussed as bio-inspired realizations, aiming at closing the gap between taxis strategies of living creatures and those of functional active microswarms. As collective behaviors emerge within a group, the global taxis to external stimuli guides the group to conduct overall tasks, whereas the local taxis between individuals induces synchronization and global patterns. By encoding the local orientations and programming the global stimuli, various paradigms can be introduced for coordinating and controlling such collective microrobots, from the viewpoints of fundamental science and practical applications. Therefore, by discussing the key points and difficulties associated with collective taxes of different paradigms, this review potentially offers insights into mimicking natural collective behaviors and constructing intelligent microrobotic systems for on-demand control and preassigned tasks.
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Affiliation(s)
- Fengtong Ji
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| | - Yilin Wu
- Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| | - Martin Pumera
- Faculty of Electrical Engineering and Computer Science, VSB - Technical University of Ostrava, 17. listopadu 2172/15, Ostrava, 70800, Czech Republic
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Li Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
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11
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Zhang J, Laskar A, Song J, Shklyaev OE, Mou F, Guan J, Balazs AC, Sen A. Light-Powered, Fuel-Free Oscillation, Migration, and Reversible Manipulation of Multiple Cargo Types by Micromotor Swarms. ACS NANO 2023; 17:251-262. [PMID: 36321936 DOI: 10.1021/acsnano.2c07266] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Through experiments and simulations, we show that fuel-free photoactive TiO2 microparticles can form mobile, coherent swarms in the presence of UV light, which track the subsequent movement of an irradiated spot in a fluid-filled microchamber. Multiple concurrent propulsion mechanisms (electrolyte diffusioosmotic swarming, photocatalytic expansion, and photothermal migration) control the rich collective behavior of the swarms, which provide a strategy to reversely manipulate cargo. The active swarms can autonomously pick up groups of inert particles, sort them by size, and sequentially release the sorted particles at particular locations in the microchamber. Hence, these swarms overcome three obstacles, limiting the utility of self-propelled particles. Namely, they can (1) undergo directed, long-range migration without the addition of a chemical fuel, (2) perform diverse collective behavior not possible with a single active particle, and (3) repeatedly and controllably isolate and deliver specific components of a multiparticle "cargo". Since light sources are easily fabricated, transported, and controlled, the results can facilitate the development of portable devices, providing broader access to the diagnostic and manufacturing advances enabled by microfluidics.
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Affiliation(s)
- Jianhua Zhang
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Hubei Key Laboratory of Biomass Fibers and Eco-dyeing & Finishing, College of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430200, China
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Abhrajit Laskar
- Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Jiaqi Song
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Oleg E Shklyaev
- Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Fangzhi Mou
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Jianguo Guan
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Anna C Balazs
- Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Ayusman Sen
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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12
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Ignés-Mullol J, Sagués F. Experiments with active and driven synthetic colloids in complex fluids. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2022.101636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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13
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Yuan S, Lin X, He Q. Reconfigurable assembly of colloidal motors towards interactive soft materials and systems. J Colloid Interface Sci 2022; 612:43-56. [PMID: 34974257 DOI: 10.1016/j.jcis.2021.12.135] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 12/19/2022]
Abstract
Due to the highly flexible reconfiguration of swarms, collective behaviors have provided various natural organisms with a powerful adaptivity to the complex environment. To mimic these natural systems and construct artificial intelligent soft materials, self-propelled colloidal motors that can convert diverse forms of energy into swimming-like movement in fluids afford an ideal model system at the micro-/nanoscales. Through the coupling of local gradient fields, colloidal motors driven by chemical reactions or externally physical fields can assembly into swarms with adaptivity. Here, we summarize the progress on reconfigurable assembly of colloidal motors which is driven and modulated by chemical reactions and external fields (e.g., light, ultrasonic, electric, and magnetic fields). The adaptive reconfiguration behaviors and the corresponding mechanisms are discussed in detail. The future directions and challenges are also addressed for developing colloidal motor-based interactive soft matter materials and systems with adaptation and interactive functions comparable to that of natural systems.
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Affiliation(s)
- Shurui Yuan
- Key Laboratory of Microsystems and Microstructures Manufacturing (Ministry of Education), School of Medicine and Health, Harbin Institute of Technology, YiKuangJie 2, Harbin 150080, China
| | - Xiankun Lin
- Key Laboratory of Microsystems and Microstructures Manufacturing (Ministry of Education), School of Medicine and Health, Harbin Institute of Technology, YiKuangJie 2, Harbin 150080, China.
| | - Qiang He
- Key Laboratory of Microsystems and Microstructures Manufacturing (Ministry of Education), School of Medicine and Health, Harbin Institute of Technology, YiKuangJie 2, Harbin 150080, China; Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China; Oujiang Laboratory, Wenzhou 325000, China.
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14
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Dynamic self-assembly of active particles in liquid crystals. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Sahu DK, Dhara S. Electrophoresis of metal-dielectric Janus particles with dipolar director symmetry in nematic liquid crystals. SOFT MATTER 2022; 18:1819-1824. [PMID: 35166748 DOI: 10.1039/d1sm01653a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We study the electrophoresis of metal-dielectric Janus particles with dipolar director symmetry in two nematic liquid crystals (LCs) having the same sign of conductivity anisotropy (Δσ) but opposite signs of dielectric anisotropy (Δε). The applied ac electric field is parallel and perpendicular to the director for positive and negative dielectric anisotropy LCs, respectively. We show that the Janus dipolar particles propel faster than the non-Janus dipolar particles in both LCs. The propelling speed of the Janus dipolar particles is also significantly higher compared to the quadrupolar Janus particles studied previously. We map the electroosmotic flow fields surrounding a Janus dipolar particle using microparticle image velocimetry (μ-PIV) and show that the flow on a metal hemisphere is stronger than that on a dielectric hemisphere. Altogether, Janus dipolar particles demonstrate efficient electrophoresis compared to both Janus and non-Janus quadrupolar particles. These findings may be useful for applications in active matter, microrobotic and microfluidic devices.
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Affiliation(s)
- Dinesh Kumar Sahu
- School of Physics, University of Hyderabad, Hyderabad 500 046, India.
| | - Surajit Dhara
- School of Physics, University of Hyderabad, Hyderabad 500 046, India.
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16
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Han K, Glatz A, Snezhko A. Emergence and dynamics of unconfined self-organised vortices in active magnetic roller liquids. SOFT MATTER 2021; 17:10536-10544. [PMID: 34761766 DOI: 10.1039/d1sm01086g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Actively driven colloids demonstrate complex out-of-equilibrium dynamics often rivaling self-organized patterns and collective behavior observed in living systems. Recent studies revealed the emergence of steady macroscopic states with multiple interacting vortices in an unconfined environment that emerge from the coupling between microscale particle rotation and translation. Yet, insights into the microscopic behavior during the vortex emergence, growth, and formation of a multi-vortical state remain lacking. Here, we investigate in experiments and simulations how the microscale magnetic roller behavior leads to the emergence of seed vortices, their aggregation or annihilation, and the formation of stable large-scale vortical structures. We reveal that the coupling of roller-induced hydrodynamic flows guides the local self-densifications and self-organization of the micro-rollers into seed vortices. The resulting multi-vortical state is sensitive to the external magnetic field amplitude and allows tuning the rollers' number density in a vortex and its characteristic size.
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Affiliation(s)
- Koohee Han
- Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA.
- Department of Chemical Engineering, Kyungpook National University, Daegu, Republic of Korea
| | - Andreas Glatz
- Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA.
- Department of Physics, Northern Illinois University, DeKalb, IL 60115, USA
| | - Alexey Snezhko
- Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA.
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17
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Pearce DJG, Kruse K. Properties of twisted topological defects in 2D nematic liquid crystals. SOFT MATTER 2021; 17:7408-7417. [PMID: 34318862 PMCID: PMC8356798 DOI: 10.1039/d1sm00825k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/08/2021] [Indexed: 05/11/2023]
Abstract
Topological defects are one of the most conspicuous features of liquid crystals. In two dimensional nematics, they have been shown to behave effectively as particles with both charge and orientation, which dictate their interactions. Here, we study "twisted" defects that have a radially dependent orientation. We find that twist can be partially relaxed through the creation and annihilation of defect pairs. By solving the equations for defect motion and calculating the forces on defects, we identify four distinct elements that govern the relative relaxational motion of interacting topological defects, namely attraction, repulsion, co-rotation and co-translation. The interaction of these effects can lead to intricate defect trajectories, which can be controlled by setting relevant timescales.
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Affiliation(s)
- D J G Pearce
- Department of Biochemistry, University of Geneva, 1211 Geneva, Switzerland. and Department of Theoretical Physics, University of Geneva, 1211 Geneva, Switzerland and NCCR Chemical Biology, University of Geneva, 1211 Geneva, Switzerland and Dept. of Mathematics, Massachusetts Institute of Technology, Massachusetts, USA
| | - K Kruse
- Department of Biochemistry, University of Geneva, 1211 Geneva, Switzerland. and Department of Theoretical Physics, University of Geneva, 1211 Geneva, Switzerland and NCCR Chemical Biology, University of Geneva, 1211 Geneva, Switzerland
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18
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Lavrentovich OD. Design of nematic liquid crystals to control microscale dynamics. LIQUID CRYSTALS REVIEWS 2021; 8:59-129. [PMID: 34956738 PMCID: PMC8698256 DOI: 10.1080/21680396.2021.1919576] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/11/2021] [Indexed: 05/25/2023]
Abstract
The dynamics of small particles, both living such as swimming bacteria and inanimate, such as colloidal spheres, has fascinated scientists for centuries. If one could learn how to control and streamline their chaotic motion, that would open technological opportunities in the transformation of stored or environmental energy into systematic motion, with applications in micro-robotics, transport of matter, guided morphogenesis. This review presents an approach to command microscale dynamics by replacing an isotropic medium with a liquid crystal. Orientational order and associated properties, such as elasticity, surface anchoring, and bulk anisotropy, enable new dynamic effects, ranging from the appearance and propagation of particle-like solitary waves to self-locomotion of an active droplet. By using photoalignment, the liquid crystal can be patterned into predesigned structures. In the presence of the electric field, these patterns enable the transport of solid and fluid particles through nonlinear electrokinetics rooted in anisotropy of conductivity and permittivity. Director patterns command the dynamics of swimming bacteria, guiding their trajectories, polarity of swimming, and distribution in space. This guidance is of a higher level of complexity than a simple following of the director by rod-like microorganisms. Namely, the director gradients mediate hydrodynamic interactions of bacteria to produce an active force and collective polar modes of swimming. The patterned director could also be engraved in a liquid crystal elastomer. When an elastomer coating is activated by heat or light, these patterns produce a deterministic surface topography. The director gradients define an activation force that shapes the elastomer in a manner similar to the active stresses triggering flows in active nematics. The patterned elastomer substrates could be used to define the orientation of cells in living tissues. The liquid-crystal guidance holds a major promise in achieving the goal of commanding microscale active flows.
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Affiliation(s)
- Oleg D Lavrentovich
- Advanced Materials and Liquid Crystal Institute, Department of Physics, Materials Science Graduate Program, Kent State University, Kent, OH 44242, USA
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19
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Wang Q, Zhang L. External Power-Driven Microrobotic Swarm: From Fundamental Understanding to Imaging-Guided Delivery. ACS NANO 2021; 15:149-174. [PMID: 33417764 DOI: 10.1021/acsnano.0c07753] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Untethered micro/nanorobots have been widely investigated owing to their potential in performing various tasks in different environments. The significant progress in this emerging interdisciplinary field has benefited from the distinctive features of those tiny active agents, such as wireless actuation, navigation under feedback control, and targeted delivery of small-scale objects. In recent studies, collective behaviors of these tiny machines have received tremendous attention because swarming agents can enhance the delivery capability and adaptability in complex environments and the contrast of medical imaging, thus benefiting the imaging-guided navigation and delivery. In this review, we summarize the recent research efforts on investigating collective behaviors of external power-driven micro/nanorobots, including the fundamental understanding of swarm formation, navigation, and pattern transformation. The fundamental understanding of swarming tiny machines provides the foundation for targeted delivery. We also summarize the swarm localization using different imaging techniques, including the imaging-guided delivery in biological environments. By highlighting the critical steps from understanding the fundamental interactions during swarm control to swarm localization and imaging-guided delivery applications, we envision that the microrobotic swarm provides a promising tool for delivering agents in an active, controlled manner.
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Affiliation(s)
- Qianqian Wang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Li Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
- Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
- T Stone Robotics Institute, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
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20
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Xie H, Sun M, Fan X, Lin Z, Chen W, Wang L, Dong L, He Q. Reconfigurable magnetic microrobot swarm: Multimode transformation, locomotion, and manipulation. Sci Robot 2021; 4:4/28/eaav8006. [PMID: 33137748 DOI: 10.1126/scirobotics.aav8006] [Citation(s) in RCA: 293] [Impact Index Per Article: 97.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 02/08/2019] [Indexed: 12/20/2022]
Abstract
Swimming microrobots that are energized by external magnetic fields exhibit a variety of intriguing collective behaviors, ranging from dynamic self-organization to coherent motion; however, achieving multiple, desired collective modes within one colloidal system to emulate high environmental adaptability and enhanced tasking capabilities of natural swarms is challenging. Here, we present a strategy that uses alternating magnetic fields to program hematite colloidal particles into liquid, chain, vortex, and ribbon-like microrobotic swarms and enables fast and reversible transformations between them. The chain is characterized by passing through confined narrow channels, and the herring school-like ribbon procession is capable of large-area synchronized manipulation, whereas the colony-like vortex can aggregate at a high density toward coordinated handling of heavy loads. Using the developed discrete particle simulation methods, we investigated generation mechanisms of these four swarms, as well as the "tank-treading" motion of the chain and vortex merging. In addition, the swarms can be programmed to steer in any direction with excellent maneuverability, and the vortex's chirality can be rapidly switched with high pattern stability. This reconfigurable microrobot swarm can provide versatile collective modes to address environmental variations or multitasking requirements; it has potential to investigate fundamentals in living systems and to serve as a functional bio-microrobot system for biomedicine.
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Affiliation(s)
- Hui Xie
- State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, Harbin 150001, China.
| | - Mengmeng Sun
- State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, Harbin 150001, China
| | - Xinjian Fan
- State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, Harbin 150001, China
| | - Zhihua Lin
- State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, Harbin 150001, China
| | - Weinan Chen
- State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, Harbin 150001, China
| | - Lei Wang
- State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, Harbin 150001, China
| | - Lixin Dong
- Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA. .,Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China
| | - Qiang He
- State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, Harbin 150001, China.
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21
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Yu J, Yang L, Du X, Chen H, Xu T, Zhang L. Adaptive Pattern and Motion Control of Magnetic Microrobotic Swarms. IEEE T ROBOT 2021. [DOI: 10.1109/tro.2021.3130432] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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22
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Zhou Z, Hou Z, Pei Y. Reconfigurable Particle Swarm Robotics Powered by Acoustic Vibration Tweezer. Soft Robot 2020; 8:735-743. [PMID: 33216709 DOI: 10.1089/soro.2020.0050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Inspired by natural swarms such as bees and ants, various types of swarm robotic systems have been developed to work together to complete tasks that transcend individual capabilities. Autonomous robots controlled by collective algorithm and colloidal swarms energized by external field have been designed in an attempt to emulate collective behaviors in nature. However, either sophisticated hardware designs or active agents with special electromagnetic properties and microstructural designs are needed. Here, for the first time, we create a swarm robotic system that can make any granular materials an active swarm robot by acoustic vibration tweezer. It should be noted that the particles energized by only one vibration generator are ordinary sand without any microstructural design. Therefore, it is the simplest and lowest cost swarm robot. Particles can display a solid-like aggregate, which is capable of robustly carrying and transporting an object that is about 1 million times heavier than a single particle. Moreover, through the cooperation of two swarm robots, we can achieve cooperative transport of a stick with a length of 1000 times the diameter of a single particle. The particle robot can move in a fluid-like amorphous group, which can change its own shape to adapt to the surrounding environment, thus having a strong environmental adaptability. Besides, it can move quickly (about 600 times the particle diameter per second) in a discrete state. Within one certain particle system, the particle swarm robot can emulate diverse biomimetic collective behaviors through navigated locomotion, multimode transformation, and cooperative transport.
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Affiliation(s)
- Zhitao Zhou
- State Key Lab for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China
| | - Zewei Hou
- State Key Lab for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China
| | - Yongmao Pei
- State Key Lab for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China
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23
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24
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Ji F, Jin D, Wang B, Zhang L. Light-Driven Hovering of a Magnetic Microswarm in Fluid. ACS NANO 2020; 14:6990-6998. [PMID: 32463226 DOI: 10.1021/acsnano.0c01464] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Swarm behaviors are nature's strategies for performing cooperative work, and extensive research has been aimed at emulating these strategies in engineering systems. However, the implementation of vertical motion and construction of a 3D structure are still challenging. Herein, we propose a simple strategy for creating a hybrid-driven paramagnetic tornado-like microswarm in an aqueous solution by integrating the use of a magnetic field and light. The precession of a magnetic field results in in-plane rotation, and light promotes the conversion of a planar microswarm to a microswarm tornado, thus realizing the transition from 2D to 3D patterns. This 3D microswarm is capable of performing reversible, vertical mass transportation. The reconfigurable collective behavior of the swarm from 2D to 3D motion consists of rising, hovering, oscillation, and landing stages. Moreover, this 3D tornado-like microswarm is capable of controlling the chemical reaction rate of the liquid in which it is deployed, for example, the degradation of methylene blue. The experimental results unveil that the tornado-like microswarm can enhance the overall degradation while holding the reactant nearby and inside it because of the flow difference between near and far regions of the microswarm tornado. Furthermore, by applying an oscillating magnetic field, the 3D microswarm can process the trapped methylene blue for on-demand degradation. The microswarm tornado is demonstrated to provide a method for collective vertical transportation and inspire ideas for mimicking 3D swarm behaviors in order to apply the functional performance to biomedical, catalytic, and micro-/nanoengineering applications.
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Affiliation(s)
- Fengtong Ji
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Sha Tin, Hong Kong, China
| | - Dongdong Jin
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Sha Tin, New Territories, Hong Kong, China
| | - Ben Wang
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Sha Tin, New Territories, Hong Kong, China
| | - Li Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Sha Tin, Hong Kong, China
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Sha Tin, New Territories, Hong Kong, China
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25
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Gompper G, Winkler RG, Speck T, Solon A, Nardini C, Peruani F, Löwen H, Golestanian R, Kaupp UB, Alvarez L, Kiørboe T, Lauga E, Poon WCK, DeSimone A, Muiños-Landin S, Fischer A, Söker NA, Cichos F, Kapral R, Gaspard P, Ripoll M, Sagues F, Doostmohammadi A, Yeomans JM, Aranson IS, Bechinger C, Stark H, Hemelrijk CK, Nedelec FJ, Sarkar T, Aryaksama T, Lacroix M, Duclos G, Yashunsky V, Silberzan P, Arroyo M, Kale S. The 2020 motile active matter roadmap. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:193001. [PMID: 32058979 DOI: 10.1088/1361-648x/ab6348] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Activity and autonomous motion are fundamental in living and engineering systems. This has stimulated the new field of 'active matter' in recent years, which focuses on the physical aspects of propulsion mechanisms, and on motility-induced emergent collective behavior of a larger number of identical agents. The scale of agents ranges from nanomotors and microswimmers, to cells, fish, birds, and people. Inspired by biological microswimmers, various designs of autonomous synthetic nano- and micromachines have been proposed. Such machines provide the basis for multifunctional, highly responsive, intelligent (artificial) active materials, which exhibit emergent behavior and the ability to perform tasks in response to external stimuli. A major challenge for understanding and designing active matter is their inherent nonequilibrium nature due to persistent energy consumption, which invalidates equilibrium concepts such as free energy, detailed balance, and time-reversal symmetry. Unraveling, predicting, and controlling the behavior of active matter is a truly interdisciplinary endeavor at the interface of biology, chemistry, ecology, engineering, mathematics, and physics. The vast complexity of phenomena and mechanisms involved in the self-organization and dynamics of motile active matter comprises a major challenge. Hence, to advance, and eventually reach a comprehensive understanding, this important research area requires a concerted, synergetic approach of the various disciplines. The 2020 motile active matter roadmap of Journal of Physics: Condensed Matter addresses the current state of the art of the field and provides guidance for both students as well as established scientists in their efforts to advance this fascinating area.
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Affiliation(s)
- Gerhard Gompper
- Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
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26
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Pagès JM, Ignés-Mullol J, Sagués F. Anomalous Diffusion of Motile Colloids Dispersed in Liquid Crystals. PHYSICAL REVIEW LETTERS 2019; 122:198001. [PMID: 31144957 DOI: 10.1103/physrevlett.122.198001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Indexed: 06/09/2023]
Abstract
We study the superdiffusion of driven colloidal particles dispersed in a nematic liquid crystal. While motion is ballistic in the driving direction, our experiments show that transversal fluctuations become superdiffusive depending on the topological defect pattern around the inclusions. The phenomenon can be reproduced with different driving methods and propulsion speeds, while it is strongly dependent on particle size and temperature. We propose a mechanism based on the geometry of the liquid crystal backflow around the inclusions to justify the persistence of thermal fluctuations and to explain the observed temperature and particle size dependence of the superdiffusive behavior based on material and geometrical parameters.
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Affiliation(s)
- Josep M Pagès
- Departament de Ciència de Materials i Química Física, and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
| | - Jordi Ignés-Mullol
- Departament de Ciència de Materials i Química Física, and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
| | - Francesc Sagués
- Departament de Ciència de Materials i Química Física, and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
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27
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Peng C, Lavrentovich OD. Liquid Crystals-Enabled AC Electrokinetics. MICROMACHINES 2019; 10:E45. [PMID: 30634568 PMCID: PMC6356904 DOI: 10.3390/mi10010045] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/01/2019] [Accepted: 01/01/2019] [Indexed: 11/17/2022]
Abstract
Phenomena of electrically driven fluid flows, known as electro-osmosis, and particle transport in a liquid electrolyte, known as electrophoresis, collectively form a subject of electrokinetics. Electrokinetics shows a great potential in microscopic manipulation of matter for various scientific and technological applications. Electrokinetics is usually studied for isotropic electrolytes. Recently it has been demonstrated that replacement of an isotropic electrolyte with an anisotropic, or liquid crystal (LC), electrolyte, brings about entirely new mechanisms of spatial charge formation and electrokinetic effects. This review presents the main features of liquid crystal-enabled electrokinetics (LCEK) rooted in the field-assisted separation of electric charges at deformations of the director that describes local molecular orientation of the LC. Since the electric field separates the charges and then drives the charges, the resulting electro-osmotic and electrophoretic velocities grow as the square of the applied electric field. We describe a number of related phenomena, such as alternating current (AC) LC-enabled electrophoresis of colloidal solid particles and fluid droplets in uniform and spatially-patterned LCs, swarming of colloids guided by photoactivated surface patterns, control of LCEK polarity through the material properties of the LC electrolyte, LCEK-assisted mixing at microscale, separation and sorting of small particles. LC-enabled electrokinetics brings a new dimension to our ability to manipulate dynamics of matter at small scales and holds a major promise for future technologies of microfluidics, pumping, mixing, sensing, and diagnostics.
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Affiliation(s)
- Chenhui Peng
- Department of Physics and Materials Science, The University of Memphis, Memphis, TN 38152, USA.
| | - Oleg D Lavrentovich
- Department of Physics and Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
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28
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Pagès JM, Straube AV, Tierno P, Ignés-Mullol J, Sagués F. Inhomogeneous assembly of driven nematic colloids. SOFT MATTER 2019; 15:312-320. [PMID: 30556080 DOI: 10.1039/c8sm02101e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present a quantitative analysis of the nonequilibrium assembly of colloidal particles dispersed in a nematic liquid crystal. The driven particles assemble into reconfigurable circular clusters by liquid-crystal-enabled electrokinetic phenomena generated by an AC electric field that provides propulsion along the local director. We identify the coexistence of different aggregation states, including a central, jammed core, where short-range elastic attraction dominates, surrounded by a liquid-like corona where particles retain their mobility but reach a mechanical equilibrium that we rationalize in terms of a balance between centripetal phoretic drive and pairwise repulsion. An analysis of the compressible liquid-like region reveals a linear density profile that can be tuned with the field frequency, and a bond-orientational order that reaches a maximum at intermediate packing densities, where elastic effects are minimized. Since the phoretic propulsion force acts also on assembled particles, we compute the mechanical pressure and show that a hard-disk equation of state can be used to describe the assembly of this driven system.
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Affiliation(s)
- Josep M Pagès
- Departament de Ciència de Materials i Química Física, Universitat de Barcelona, Catalonia, Spain.
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29
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Conklin C, Tovkach OM, Viñals J, Calderer MC, Golovaty D, Lavrentovich OD, Walkington NJ. Electrokinetic effects in nematic suspensions: Single-particle electro-osmosis and interparticle interactions. Phys Rev E 2018; 98:022703. [PMID: 30253587 DOI: 10.1103/physreve.98.022703] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Indexed: 11/07/2022]
Abstract
Electrokinetic phenomena in a nematic suspension are considered when one or more dielectric particles are suspended in a liquid crystal matrix in its nematic phase. The long-range orientational order of the nematic constitutes a fluid with anisotropic properties. This anisotropy enables charge separation in the bulk under an applied electric field, and leads to streaming flows even when the applied field is oscillatory. In the cases considered, charge separation is seen to result from director field distortions in the matrix that are created by the suspended particles. We use a recently introduced electrokinetic model to study the motion of a single-particle hyperbolic hedgehog pair. We find this motion to be parallel to the defect-particle center axis, independent of field orientation. For a two-particle configuration, we find that the relative force of electrokinetic origin is attractive in the case of particles with perpendicular director anchoring, and repulsive for particles with tangential director anchoring. The study reveals large scale flow properties that are respectively derived from the topology of the configuration alone and from short scale hydrodynamics phenomena in the vicinity of the particle and defect.
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Affiliation(s)
- Christopher Conklin
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - O M Tovkach
- Department of Mathematics, The University of Akron, Akron, Ohio 44325, USA.,Bogolyubov Institute for Theoretical Physics, NAS of Ukraine, Metrologichna 14-b, Kyiv 03680, Ukraine
| | - Jorge Viñals
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - M Carme Calderer
- School of Mathematics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Dmitry Golovaty
- Department of Mathematics, The University of Akron, Akron, Ohio 44325, USA
| | - Oleg D Lavrentovich
- Liquid Crystal Institute, Department of Physics and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, USA
| | - Noel J Walkington
- Department of Mathematical Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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30
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Solomon MJ. Tools and Functions of Reconfigurable Colloidal Assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11205-11219. [PMID: 29397742 DOI: 10.1021/acs.langmuir.7b03748] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We review work in reconfigurable colloidal assembly, a field in which rapid, back-and-forth transitions between the equilibrium states of colloidal self-assembly are accomplished by dynamic manipulation of the size, shape, and interaction potential of colloids, as well as the magnitude and direction of the fields applied to them. It is distinguished from the study of colloidal phase transitions by the centrality of thermodynamic variables and colloidal properties that are time switchable; by the applicability of these changes to generate transitions in assembled colloids that may be spatially localized; and by its incorporation of the effects of generalized potentials due to, for example, applied electric and magnetic fields. By drawing upon current progress in the field, we propose a matrix classification of reconfigurable colloidal systems based on the tool used and function performed by reconfiguration. The classification distinguishes between the multiple means by which reconfigurable assembly can be accomplished (i.e., the tools of reconfiguration) and the different kinds of structural transitions that can be achieved by it (i.e., the functions of reconfiguration). In the first case, the tools of reconfiguration can be broadly classed as (i) those that control the colloidal contribution to the system entropy-as through volumetric and/or shape changes of the particles; (ii) those that control the internal energy of the colloids-as through manipulation of colloidal interaction potentials; and (iii) those that control the spatially resolved potential energy that is imposed on the colloids-as through the introduction of field-induced phoretic mechanisms that yield colloidal displacement and accumulation. In the second case, the functions of reconfiguration include reversible: (i) transformation between different phases-including fluid, cluster, gel, and crystal structures; (ii) manipulation of the spacing between colloids in crystals and clusters; and (iii) translation, rotation, or shape-change of finite-size objects self-assembled from colloids. With this classification in hand, we correlate the current limits on the spatiotemporal scales for reconfigurable colloidal assembly and identify a set of future research challenges.
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Manipulation of emergent vortices in swarms of magnetic rollers. Nat Commun 2018; 9:2344. [PMID: 29904114 PMCID: PMC6002404 DOI: 10.1038/s41467-018-04765-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 05/18/2018] [Indexed: 11/08/2022] Open
Abstract
Active colloids are an emergent class of out-of-equilibrium materials demonstrating complex collective phases and tunable functionalities. Microscopic particles energized by external fields exhibit a plethora of fascinating collective phenomena, yet mechanisms of control and manipulation of active phases often remains lacking. Here we report the emergence of unconfined macroscopic vortices in a system of ferromagnetic rollers energized by a vertical alternating magnetic field and elucidate the complex nature of a magnetic roller-vortex interactions with inert scatterers. We demonstrate that active self-organized vortices have an ability to spontaneously switch the direction of rotation and move across the surface. We reveal the capability of certain non-active particles to pin the vortex and manipulate its dynamics. Building on our findings, we demonstrate the potential of magnetic roller vortices to effectively capture and transport inert particles at the microscale.
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Guillamat P, Kos Ž, Hardoüin J, Ignés-Mullol J, Ravnik M, Sagués F. Active nematic emulsions. SCIENCE ADVANCES 2018; 4:eaao1470. [PMID: 29740605 PMCID: PMC5938235 DOI: 10.1126/sciadv.aao1470] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 02/16/2018] [Indexed: 05/11/2023]
Abstract
The formation of emulsions from multiple immiscible fluids is governed by classical concepts such as surface tension, differential chemical affinity and viscosity, and the action of surface-active agents. Much less is known about emulsification when one of the components is active and thus inherently not constrained by the laws of thermodynamic equilibrium. We demonstrate one such realization consisting in the encapsulation of an active liquid crystal (LC)-like gel, based on microtubules and kinesin molecular motors, into a thermotropic LC. These active nematic emulsions exhibit a variety of dynamic behaviors that arise from the cross-talk between topological defects separately residing in the active and passive components. Using numerical simulations, we show a feedback mechanism by which active flows continuously drive the passive defects that, in response, resolve the otherwise degenerated trajectories of the active defects. Our experiments show that the choice of surfactant, which stabilizes the active/passive interface, allows tuning the regularity of the self-sustained dynamic events. The hybrid active-passive system demonstrated here provides new perspectives for dynamic self-assembly driven by an active material but regulated by the equilibrium properties of the passive component.
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Affiliation(s)
- Pau Guillamat
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia
- Institute of Nanoscience and Nanotechnology, IN2UB, University de Barcelona, Barcelona, Catalonia
| | - Žiga Kos
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
| | - Jérôme Hardoüin
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia
- Institute of Nanoscience and Nanotechnology, IN2UB, University de Barcelona, Barcelona, Catalonia
| | - Jordi Ignés-Mullol
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia
- Institute of Nanoscience and Nanotechnology, IN2UB, University de Barcelona, Barcelona, Catalonia
- Corresponding author.
| | - Miha Ravnik
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
- Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Francesc Sagués
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia
- Institute of Nanoscience and Nanotechnology, IN2UB, University de Barcelona, Barcelona, Catalonia
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Light-Controlled Swarming and Assembly of Colloidal Particles. MICROMACHINES 2018; 9:mi9020088. [PMID: 30393364 PMCID: PMC6187466 DOI: 10.3390/mi9020088] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 02/04/2018] [Accepted: 02/11/2018] [Indexed: 12/02/2022]
Abstract
Swarms and assemblies are ubiquitous in nature and they can perform complex collective behaviors and cooperative functions that they cannot accomplish individually. In response to light, some colloidal particles (CPs), including light active and passive CPs, can mimic their counterparts in nature and organize into complex structures that exhibit collective functions with remote controllability and high temporospatial precision. In this review, we firstly analyze the structural characteristics of swarms and assemblies of CPs and point out that light-controlled swarming and assembly of CPs are generally achieved by constructing light-responsive interactions between CPs. Then, we summarize in detail the recent advances in light-controlled swarming and assembly of CPs based on the interactions arisen from optical forces, photochemical reactions, photothermal effects, and photoisomerizations, as well as their potential applications. In the end, we also envision some challenges and future prospects of light-controlled swarming and assembly of CPs. With the increasing innovations in mechanisms and control strategies with easy operation, low cost, and arbitrary applicability, light-controlled swarming and assembly of CPs may be employed to manufacture programmable materials and reconfigurable robots for cooperative grasping, collective cargo transportation, and micro- and nanoengineering.
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Elementary Flow Field Profiles of Micro-Swimmers in Weakly Anisotropic Nematic Fluids: Stokeslet, Stresslet, Rotlet and Source Flows. FLUIDS 2018. [DOI: 10.3390/fluids3010015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Pismen LM, Sagués F. Viscous dissipation and dynamics of defects in an active nematic interface ⋆. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2017; 40:92. [PMID: 29063989 DOI: 10.1140/epje/i2017-11582-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/11/2017] [Indexed: 06/07/2023]
Abstract
We consider active flow and dynamics of topological defects in an active nematic interfacial layer confined between immissible viscous fluid layers. The velocity of defects is determined by asymptotic matching of solutions in the defect core and the far field. Self-propulsion of positive defects along the direction of their "comet tails" is identified as the principal deterministic component of defect dynamics, while topological and hydrodynamic interactions among mobile defects is responsible for quasi-random jitter.
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Affiliation(s)
- Len M Pismen
- Department of Chemical Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
| | - Francesc Sagués
- Departament of Materials Science and Physical Chemistry, Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, Martí Franquès 1, 08028, Barcelona, Spain
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Cross-talk between topological defects in different fields revealed by nematic microfluidics. Proc Natl Acad Sci U S A 2017; 114:E5771-E5777. [PMID: 28674012 DOI: 10.1073/pnas.1702777114] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Topological defects are singularities in material fields that play a vital role across a range of systems: from cosmic microwave background polarization to superconductors and biological materials. Although topological defects and their mutual interactions have been extensively studied, little is known about the interplay between defects in different fields-especially when they coevolve-within the same physical system. Here, using nematic microfluidics, we study the cross-talk of topological defects in two different material fields-the velocity field and the molecular orientational field. Specifically, we generate hydrodynamic stagnation points of different topological charges at the center of star-shaped microfluidic junctions, which then interact with emergent topological defects in the orientational field of the nematic director. We combine experiments and analytical and numerical calculations to show that a hydrodynamic singularity of a given topological charge can nucleate a nematic defect of equal topological charge and corroborate this by creating [Formula: see text], [Formula: see text], and [Formula: see text] topological defects in four-, six-, and eight-arm junctions. Our work is an attempt toward understanding materials that are governed by distinctly multifield topology, where disparate topology-carrying fields are coupled and concertedly determine the material properties and response.
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Conklin C, Viñals J. Electrokinetic flows in liquid crystal thin films with fixed anchoring. SOFT MATTER 2017; 13:725-739. [PMID: 27973626 DOI: 10.1039/c6sm02393b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We study ionic and mass transport in a liquid crystalline fluid film in its nematic phase under an applied electrostatic field. Both analytic and numerical solutions are given for some prototypical configurations of interest in electrokinetics: thin films with spatially nonuniform nematic director that are either periodic or comprise a set of isolated disclinations. We present a quantitative description of the mechanisms inducing spatial charge separation in the nematic, and of the structure and magnitude of the resulting flows. The fundamental solutions for the charge distribution and flow velocities induced by disclinations of topological charge m = -1/2, 1/2 and 1 are given. These solutions allow the analysis of several designer flows, such as "pusher" flows created by three colinear disclinations, the flow induced by an immersed spherical particle (equivalent to an m = 1 defect) and its accompanying m = -1 hyperbolic hedgehog defect, and the mechanism behind nonlinear ionic mobilities when the imposed field is perpendicular to the line joining the defects.
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Affiliation(s)
- Christopher Conklin
- School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, USA.
| | - Jorge Viñals
- School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, USA.
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Guillamat P, Ignés-Mullol J, Shankar S, Marchetti MC, Sagués F. Probing the shear viscosity of an active nematic film. Phys Rev E 2016; 94:060602. [PMID: 28085294 DOI: 10.1103/physreve.94.060602] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Indexed: 12/12/2022]
Abstract
In vitro reconstituted active systems, such as the adenosine triphosphate (ATP)-driven microtubule bundle suspension developed by the Dogic group [T. Sanchez, D. T. Chen, S. J. DeCamp, M. Heymann, and Z. Dogic, Nature (London) 491, 431 (2012)10.1038/nature11591], provide a fertile testing ground for elucidating the phenomenology of active liquid crystalline states. Controlling such novel phases of matter crucially depends on our knowledge of their material and physical properties. In this Rapid Communication, we show that the shear viscosity of an active nematic film can be probed by varying its hydrodynamic coupling to a bounding oil layer. Using the motion of disclinations as intrinsic tracers of the flow field and a hydrodynamic model, we obtain an estimate for the shear viscosity of the nematic film. Knowing this now provides us with an additional handle for robust and precision tunable control of the emergent dynamics of active fluids.
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Affiliation(s)
- Pau Guillamat
- Departament de Química Física and Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
| | - Jordi Ignés-Mullol
- Departament de Química Física and Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
| | - Suraj Shankar
- Physics Department and Syracuse Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - M Cristina Marchetti
- Physics Department and Syracuse Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - Francesc Sagués
- Departament de Química Física and Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
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Sasaki Y, Hoshikawa H, Seto T, Kobayashi F, Jampani VSR, Herminghaus S, Bahr C, Orihara H. Direct visualization of spatiotemporal structure of self-assembled colloidal particles in electrohydrodynamic flow of a nematic liquid crystal. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3815-3819. [PMID: 25774695 DOI: 10.1021/acs.langmuir.5b00450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Characterization of spatiotemporal dynamics is of vital importance to soft matter systems far from equilibrium. Using a confocal laser scanning microscopy, we directly reveal three-dimensional motion of surface-modified particles in the electrohydrodynamic convection of a nematic liquid crystal. Particularly, visualizing a caterpillar-like motion of a self-assembled colloidal chain demonstrates the mechanism of the persistent transport enabled by the elastic, electric, and hydrodynamic contributions. We also precisely show how the particles' trajectory is spatially modified by simply changing the surface boundary condition.
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Affiliation(s)
- Yuji Sasaki
- †Division of Applied Physics, Faculty of Engineering, Hokkaido University, North 13 West 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
| | - Hikaru Hoshikawa
- †Division of Applied Physics, Faculty of Engineering, Hokkaido University, North 13 West 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
| | - Takafumi Seto
- †Division of Applied Physics, Faculty of Engineering, Hokkaido University, North 13 West 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
| | - Fumiaki Kobayashi
- †Division of Applied Physics, Faculty of Engineering, Hokkaido University, North 13 West 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
| | - V S R Jampani
- ‡Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany
| | - Stephan Herminghaus
- ‡Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany
| | - Christian Bahr
- ‡Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany
| | - Hiroshi Orihara
- †Division of Applied Physics, Faculty of Engineering, Hokkaido University, North 13 West 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
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Hernandez-Navarro S, Tierno P, Ignes-Mullol J, Sagues F. Nematic Colloidal Swarms Assembled and Transported on Photosensitive Surfaces. IEEE Trans Nanobioscience 2015; 14:267-71. [DOI: 10.1109/tnb.2015.2389873] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Sánchez S, Soler L, Katuri J. Chemically powered micro- and nanomotors. Angew Chem Int Ed Engl 2014; 54:1414-44. [PMID: 25504117 DOI: 10.1002/anie.201406096] [Citation(s) in RCA: 598] [Impact Index Per Article: 59.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Indexed: 11/08/2022]
Abstract
Chemically powered micro- and nanomotors are small devices that are self-propelled by catalytic reactions in fluids. Taking inspiration from biomotors, scientists are aiming to find the best architecture for self-propulsion, understand the mechanisms of motion, and develop accurate control over the motion. Remotely guided nanomotors can transport cargo to desired targets, drill into biomaterials, sense their environment, mix or pump fluids, and clean polluted water. This Review summarizes the major advances in the growing field of catalytic nanomotors, which started ten years ago.
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Affiliation(s)
- Samuel Sánchez
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart (Germany) http://www.is.mpg.de/sanchez; Institute for Bioengineering of Catalonia (IBEC), 08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona (Spain).
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