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Evangelou D, Pournara AD, Karagianni VI, Dimitriou C, Andreou EK, Deligiannakis Y, Armatas GS, Manos MJ. Just Soaping Them: The Simplest Method for Converting Metal Organic Frameworks into Superhydrophobic Materials. ACS APPLIED MATERIALS & INTERFACES 2024; 16:12672-12685. [PMID: 38421719 PMCID: PMC11191008 DOI: 10.1021/acsami.3c19536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/15/2024] [Accepted: 02/21/2024] [Indexed: 03/02/2024]
Abstract
The incorporation of superhydrophobic properties into metal organic framework (MOF) materials is highly desirable to enhance their hydrolytic stability, gas capture selectivity in the presence of humidity and efficiency in oil-water separations, among others. The existing strategies for inducing superhydrophobicity into MOFs have several weaknesses, such as increased cost, utilization of toxic reagents and solvents, applicability for limited MOFs, etc. Here, we report the simplest, most eco-friendly, and cost-effective process to impart superhydrophobicity to MOFs, involving a rapid (90 min) treatment of MOF materials with solutions of sodium oleate, a main component of soap. The method can be applied to both hydrolytically stable and unstable MOFs, with the porosity of modified MOFs approaching, in most cases, that of the pristine materials. Interestingly, this approach was used to isolate superhydrophobic magnetic MOF composites, and one of these materials formed stable liquid marbles, whose motion could be easily guided using an external magnetic field. We also successfully fabricated superhydrophobic MOF-coated cotton fabric and fiber composites. These composites exhibited exceptional oil sorption properties achieving rapid removal of floating crude oil from water, as well as efficient purification of oil-in-water emulsions. They are also regenerable and reusable for multiple sorption processes. Overall, the results described here pave the way for an unprecedented expansion of the family of MOF-based superhydrophobic materials, as virtually any MOF could be converted into a superhydrophobic compound by applying the new synthetic approach.
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Affiliation(s)
| | | | | | - Christos Dimitriou
- Department
of Physics, University of Ioannina, Ioannina GR-45110, Greece
| | - Evangelos K. Andreou
- Department
of Materials Science and Technology, University
of Crete, Heraklion GR-70013, Greece
| | | | - Gerasimos S. Armatas
- Department
of Materials Science and Technology, University
of Crete, Heraklion GR-70013, Greece
| | - Manolis J. Manos
- Department
of Chemistry, University of Ioannina, Ioannina GR-45110, Greece
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2
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Nnachi RC, Sui N, Ke B, Luo Z, Bhalla N, He D, Yang Z. Biosensors for rapid detection of bacterial pathogens in water, food and environment. ENVIRONMENT INTERNATIONAL 2022; 166:107357. [PMID: 35777116 DOI: 10.1016/j.envint.2022.107357] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/10/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Conventional techniques (e.g., culture-based method) for bacterial detection typically require a central laboratory and well-trained technicians, which may take several hours or days. However, recent developments within various disciplines of science and engineering have led to a major paradigm shift in how microorganisms can be detected. The analytical sensors which are widely used for medical applications in the literature are being extended for rapid and on-site monitoring of the bacterial pathogens in food, water and the environment. Especially, within the low-resource settings such as low and middle-income countries, due to the advantages of low cost, rapidness and potential for field-testing, their use is indispensable for sustainable development of the regions. Within this context, this paper discusses analytical methods and biosensors which can be used to ensure food safety, water quality and environmental monitoring. In brief, most of our discussion is focused on various rapid sensors including biosensors and microfluidic chips. The analytical performances such as the sensitivity, specificity and usability of these sensors, as well as a brief comparison with the conventional techniques for bacteria detection, form the core part of the discussion. Furthermore, we provide a holistic viewpoint on how future research should focus on exploring the synergy of different sensing technologies by developing an integrated multiplexed, sensitive and accurate sensors that will enable rapid detection for food safety, water and environmental monitoring.
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Affiliation(s)
- Raphael Chukwuka Nnachi
- School of Water, Energy and Environment, Cranfield University, Milton Keynes MK43, 0AL, United Kingdom
| | - Ning Sui
- College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Bowen Ke
- Laboratory of Anesthesiology & Critical Care Medicine, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan 61004, PR China
| | - Zhenhua Luo
- School of Water, Energy and Environment, Cranfield University, Milton Keynes MK43, 0AL, United Kingdom
| | - Nikhil Bhalla
- Nanotechnology and Integrated Bioengineering Centre (NIBEC), School of Engineering, Ulster University, Shore Road, BT37 0QB Jordanstown, Northern Ireland, United Kingdom; Healthcare Technology Hub, Ulster University, Jordanstown Shore Road, BT37 0QB, Northern Ireland, United Kingdom
| | - Daping He
- School of Science, Wuhan University of Technology, Wuhan 430070, China
| | - Zhugen Yang
- School of Water, Energy and Environment, Cranfield University, Milton Keynes MK43, 0AL, United Kingdom.
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3
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Bartlett S, Gao AK, Yung YL. Computation by Convective Logic Gates and Thermal Communication. ARTIFICIAL LIFE 2022; 28:96-107. [PMID: 35358297 DOI: 10.1162/artl_a_00358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We demonstrate a novel computational architecture based on fluid convection logic gates and heat flux-mediated information flows. Our previous work demonstrated that Boolean logic operations can be performed by thermally driven convection flows. In this work, we use numerical simulations to demonstrate a different , but universal Boolean logic operation (NOR), performed by simpler convective gates. The gates in the present work do not rely on obstacle flows or periodic boundary conditions, a significant improvement in terms of experimental realizability. Conductive heat transfer links can be used to connect the convective gates, and we demonstrate this with the example of binary half addition. These simulated circuits could be constructed in an experimental setting with modern, 2-dimensional fluidics equipment, such as a thin layer of fluid between acrylic plates. The presented approach thus introduces a new realm of unconventional, thermal fluid-based computation.
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Affiliation(s)
- Stuart Bartlett
- California Institute of Technology, Division of Geological and Planetary Sciences.
- Tokyo Institute of Technology, Earth-Life Science Institute
| | - Andrew K Gao
- California Institute of Technology, Division of Geological and Planetary Sciences
- Peking University, Yuanpei College
| | - Yuk L Yung
- California Institute of Technology, Division of Geological and Planetary Sciences
- NASA Jet Propulsion Laboratory
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4
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Ooi CH, Vadivelu R, Jin J, Sreejith KR, Singha P, Nguyen NK, Nguyen NT. Liquid marble-based digital microfluidics - fundamentals and applications. LAB ON A CHIP 2021; 21:1199-1216. [PMID: 33656019 DOI: 10.1039/d0lc01290d] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Liquid marbles are droplets with volume typically on the order of microliters coated with hydrophobic powder. Their versatility, ease of use and low cost make liquid marbles an attractive platform for digital microfluidics. This paper provides the state of the art of discoveries in the physics of liquid marbles and their practical applications. The paper first discusses the fundamental properties of liquid marbles, followed by the summary of different techniques for the synthesis of liquid marbles. Next, manipulation techniques for handling liquid marbles are discussed. Applications of liquid marbles are categorised according to their use as chemical and biological reactors. The paper concludes with perspectives on the future development of liquid marble-based digital microfluidics.
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Affiliation(s)
- Chin Hong Ooi
- Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland 4111, Australia.
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5
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Abstract
A substrate does not have to be solid to compute. It is possible to make a computer purely from a liquid. I demonstrate this using a variety of experimental prototypes where a liquid carries signals, actuates mechanical computing devices and hosts chemical reactions. We show hydraulic mathematical machines that compute functions based on mass transfer analogies. I discuss several prototypes of computing devices that employ fluid flows and jets. They are fluid mappers, where the fluid flow explores a geometrically constrained space to find an optimal way around, e.g. the shortest path in a maze, and fluid logic devices where fluid jet streams interact at the junctions of inlets and results of the computation are represented by fluid jets at selected outlets. Fluid mappers and fluidic logic devices compute continuously valued functions albeit discretized. There is also an opportunity to do discrete operation directly by representing information by droplets and liquid marbles (droplets coated by hydrophobic powder). There, computation is implemented at the sites, in time and space, where droplets collide one with another. The liquid computers mentioned above use liquid as signal carrier or actuator: the exact nature of the liquid is not that important. What is inside the liquid becomes crucial when reaction-diffusion liquid-phase computing devices come into play: there, the liquid hosts families of chemical species that interact with each other in a massive-parallel fashion. I shall illustrate a range of computational tasks, including computational geometry, implementable by excitation wave fronts in nonlinear active chemical medium. The overview will enable scientists and engineers to understand how vast is the variety of liquid computers and will inspire them to design their own experimental laboratory prototypes. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'.
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Affiliation(s)
- Andrew Adamatzky
- Unconventional Computing Lab, Department of Computer Science and Creative Technologies, University of the West of England , Bristol , UK
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6
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Draper TC, Phillips N, Weerasekera R, Mayne R, Fullarton C, de Lacy Costello BPJ, Adamatzky A. Contactless sensing of liquid marbles for detection, characterisation & computing. LAB ON A CHIP 2020; 20:136-146. [PMID: 31777892 DOI: 10.1039/c9lc01001g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Liquid marbles (LMs) are of growing interest in many fields, including microfluidics, microreactors, sensors, and signal carriers. The generation of LMs is generally performed manually, although there has recently been a burst of publications involving 'automatic marble makers'. The characteristics of a LM is dependent on many things, including how it is generated, it is therefore important to be able to characterise LMs once made. Here is presented a novel contactless LM sensor, constructed on a PCB board with a comb-like structure of 36 interlacing electrical traces, 100 μm wide and 100 μm apart. This cheap, scalable, and easy to use sensor exploits the inherent impedance (comprised of the electrical resistance, capacitive reactance and inductive reactance) of different LMs. With it, parameters of a LM can be easily determined, without interfering with the LM. These parameters are (1) particle size of the LM coating, (2) the concentration of a NaCl solution used as the LM core, and (3) the volume of the LM. Additionally, due to the comb-like nature of the sensor, the accurate positioning (down to the inter-trace spacing) of the LM can be ascertained. The new sensor has been shown to work under both static and dynamic (mobile) conditions. The capacitance of a LM was recorded to be 0.10 pF, which compares well with the calculated value of 0.12 pF.
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Affiliation(s)
- Thomas C Draper
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS161QY, UK.
| | - Neil Phillips
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS161QY, UK.
| | - Roshan Weerasekera
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS161QY, UK. and Department of Engineering Design and Mathematics, Faculty of the Environment and Technology, University of the West of England, Bristol, BS161QY, UK
| | - Richard Mayne
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS161QY, UK. and Department of Applied Sciences, Faculty of Health and Applied Sciences, University of the West of England, Bristol, BS161QY, UK
| | - Claire Fullarton
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS161QY, UK.
| | - Ben P J de Lacy Costello
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS161QY, UK. and Institute of Biosensing Technology, Centre for Research in Biosciences, University of the West of England, Bristol, BS161QY, UK
| | - Andrew Adamatzky
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS161QY, UK.
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7
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Alp G, Alp E, Aydogan N. Magnetic liquid marbles to facilitate rapid manipulation of the oil phase: Synergistic effect of semifluorinated ligand and catanionic surfactant mixtures. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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8
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Adamatzky A, Tsompanas M, Draper TC, Fullarton C, Mayne R. Liquid Marble Photosensor. Chemphyschem 2019; 21:90-98. [PMID: 31696651 DOI: 10.1002/cphc.201900949] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 10/30/2019] [Indexed: 01/31/2023]
Affiliation(s)
- Andrew Adamatzky
- Unconventional Computing LaboratoryUniversity of the West of England, Coldharbour Lane Bristol BS16 1QY UK
| | | | - Thomas C. Draper
- Unconventional Computing LaboratoryUniversity of the West of England, Coldharbour Lane Bristol BS16 1QY UK
| | - Claire Fullarton
- Unconventional Computing LaboratoryUniversity of the West of England, Coldharbour Lane Bristol BS16 1QY UK
| | - Richard Mayne
- Unconventional Computing LaboratoryUniversity of the West of England, Coldharbour Lane Bristol BS16 1QY UK
- Department of Applied SciencesUniversity of the West of England, Coldharbour Lane Bristol BS16 1QY UK
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9
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Mayne R, Draper TC, Phillips N, Whiting JGH, Weerasekera R, Fullarton C, de Lacy Costello BPJ, Adamatzky A. Neuromorphic Liquid Marbles with Aqueous Carbon Nanotube Cores. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13182-13188. [PMID: 31525934 PMCID: PMC7007261 DOI: 10.1021/acs.langmuir.9b02552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/16/2019] [Indexed: 05/08/2023]
Abstract
Neuromorphic computing devices attempt to emulate features of biological nervous systems through mimicking the properties of synapses toward implementing the emergent properties of their counterparts, such as learning. Inspired by recent advances in the utilization of liquid marbles (LMs, microliter quantities of fluid coated in hydrophobic powder) for the creation of unconventional computing devices, we describe the development of LMs with neuromorphic properties through the use of copper coatings and 1.0 mg mL-1 carbon nanotube (CNT)-containing fluid cores. Experimentation was performed through sandwiching the LMs between two cup-style electrodes and stimulating them with repeated dc pulses at 3.0 V. Our results demonstrate that "entrainment" of CNT-filled copper LMs via periodic pulses can cause their electrical resistance to rapidly switch between high to low resistance profiles upon inverting the polarity of stimulation: the reduction in resistance between high and low profiles was approximately 88% after two rounds of entrainment. This effect was found to be reversible through reversion to the original stimulus polarity and was strengthened by repeated experimentation, as evidenced by a mean reduction in time to switching onset of 43%. These effects were not replicated in nanotube solutions not bound inside LMs. Our electrical characterization also reveals that nanotube-filled LMs exhibit pinched loop hysteresis IV profiles consistent with the description of memristors. We conclude by discussing the applications of this technology to the development of unconventional computing devices and the study of emergent characteristics in biological neural tissue.
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Affiliation(s)
- Richard Mayne
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
| | - Thomas C. Draper
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
| | - Neil Phillips
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
| | - James G. H. Whiting
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
| | - Roshan Weerasekera
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
| | - Claire Fullarton
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
| | - Ben P. J. de Lacy Costello
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
| | - Andrew Adamatzky
- Department
of Applied Sciences, Faculty of Health and Applied Sciences, Unconventional Computing
Group, Faculty of the Environment and Technology, Department of Engineering Design
and Mathematics, Faculty of the Environment and Technology, and Health Technology
Hub, University of the West of England, Frenchay Campus, Bristol BS16 1QY, U.K.
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10
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Abstract
We posit that embodied artificial intelligence is not only a computational, but also a materials problem. While the importance of material and structural properties in the control loop are well understood, materials can take an active role during control by tight integration of sensors, actuators, computation, and communication. We envision such materials to abstract functionality, therefore making the construction of intelligent robots more straightforward and robust. For example, robots could be made of bones that measure load, muscles that move, skin that provides the robot with information about the kind and location of tactile sensations ranging from pressure to texture and damage, eyes that extract high-level information, and brain material that provides computation in a scalable manner. Such materials will not resemble any existing engineered materials, but rather the heterogeneous components out of which their natural counterparts are made. We describe the state-of-the-art in so-called “robotic materials,” their opportunities for revolutionizing applications ranging from manipulation to autonomous driving by describing two recent robotic materials, a smart skin and a smart tire in more depth, and conclude with open challenges that the robotics community needs to address in collaboration with allies, such as wireless sensor network researchers and polymer scientists.
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11
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Bartlett SJ, Yung YL. Boolean logic by convective obstacle flows. Proc Math Phys Eng Sci 2019; 475:20190192. [DOI: 10.1098/rspa.2019.0192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 07/16/2019] [Indexed: 11/12/2022] Open
Abstract
We present a potential new mode of natural computing in which simple, heat-driven fluid flows perform Boolean logic operations. The system comprises a two-dimensional single-phase fluid that is heated from below and cooled from above, with two obstacles placed on the horizontal mid-plane. The obstacles remove all vertical momentum that flows into them. The horizontal momentum extraction of the obstacles is controlled in a binary fashion, and constitutes the 2-bit input. The output of the system is a thresholded measure of the energy extracted by the obstacles. Due to the existence of multiple attractors in the phase space of this system, the input–output relationships are equivalent to those of the OR, XOR or NAND gates, depending on the threshold and obstacle separation. The ability to reproduce these logical operations suggests that convective flows might have the potential to perform more general computations, despite the fact that they do not involve electronics, chemistry or multiple fluid phases.
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Affiliation(s)
- S. J. Bartlett
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Y. L. Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
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12
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Ohshio M, Yukioka S, Nguyen TL, Iimura K, Fujii S, Nakamura Y, Yusa SI. Oxidation-responsive Liquid Marbles. CHEM LETT 2019. [DOI: 10.1246/cl.190148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Maho Ohshio
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Shotaro Yukioka
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Thi Lien Nguyen
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Kenji Iimura
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
- Nanomaterials Microdevices Research Center, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
- Nanomaterials Microdevices Research Center, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Shin-ichi Yusa
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
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13
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Draper TC, Fullarton C, Mayne R, Phillips N, Canciani GE, de Lacy Costello BPJ, Adamatzky A. Mapping outcomes of liquid marble collisions. SOFT MATTER 2019; 15:3541-3551. [PMID: 30945723 DOI: 10.1039/c9sm00328b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Liquid marbles (LMs) have many promising roles in the ongoing development of microfluidics, microreactors, bioreactors, and unconventional computing. In many of these applications, the coalescence of two LMs is either required or actively discouraged, therefore it is important to study liquid marble collisions and establish parameters which enable the desired collision outcome. Recent reports on LM coalescence have focused on either two mobile LMs colliding, or an accelerating LM hitting a sessile LM with a backstop. A further possible scenario is the impact of a mobile LM against a non-supported static LM. This paper investigates such a collision, using high-speed videography for single-frame analysis. Multiple collisions were undertaken whilst varying the modified Weber number (We*) and offset ratios (X*). Parameter ranges of 1.0 < We* < 1.4 and 0.0 < X* < 0.1, resulted in a coalescence rate of approximately 50%. Whereas, parameter ranges X* > 0.25, and We* < 0.95 or We* > 1.55 resulted in 100% non-coalescence. Additionally, observations of LMs moving above a threshold velocity of 0.6 m s-1 have revealed a new and unusual deformation. Comparisons of the outcome of collisions whilst varying both the LM volume and the powder grain size have also been made, revealing a strong link. The results of this work provide a deeper understanding of LM coalescence, allowing improved control when designing future collision experiments.
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Affiliation(s)
- Thomas C Draper
- Unconventional Computing Laboratory, University of the West of England, Bristol, BS16 1QY, UK.
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14
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Bartlett SJ, Yung YL. Convective flow in the presence of a small obstacle: Symmetry breaking, attractors, hysteresis, and information. Phys Rev E 2019; 99:033103. [PMID: 30999451 DOI: 10.1103/physreve.99.033103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Indexed: 11/07/2022]
Abstract
This work explores the stability and hysteresis effects that occur when a small sink of momentum is introduced into a heat-driven, two-dimensional convective flow. As per standard fluid mechanical intuition, the system minimizes work generation and dissipation when one component of momentum is extracted. However, when the sink absorbs all incoming momentum, the system configures itself such that one of the convection plumes aligns directly with the sink. This state is the most hydrodynamically stable, but it maximizes, rather than minimizes extracted mechanical work. Furthermore, in the case of only vertical momentum extraction, there are two attractors, with different stabilities. Numerical experiments involving slow variations of the horizontal momentum extraction show a clear history dependence. This hysteresis preserves information about the system's past states, and hence represents a primitive memory. The momentum sink can also be used to manipulate the horizontal position of the flow field, with potential applications in microfluidics and laminar convection systems. This simple system exhibits the phenomena of autocatalysis (during the initial growth of the convection plumes), negative feedback (the attractors are either fully or quasistable), memory, and elementary computation.
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Affiliation(s)
- S J Bartlett
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA and Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Y L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA and Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan
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15
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Adamatzky A, Fullarton C, Phillips N, De Lacy Costello B, Draper TC. Thermal switch of oscillation frequency in Belousov-Zhabotinsky liquid marbles. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190078. [PMID: 31183147 PMCID: PMC6502391 DOI: 10.1098/rsos.190078] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/27/2019] [Indexed: 06/09/2023]
Abstract
External control of oscillation dynamics in the Belousov-Zhabotinsky (BZ) reaction is important for many applications including encoding computing schemes. When considering the BZ reaction, there are limited studies dealing with thermal cycling, particularly cooling, for external control. Recently, liquid marbles (LMs) have been demonstrated as a means of confining the BZ reaction in a system containing a solid-liquid interface. BZ LMs were prepared by rolling 50 μl droplets in polyethylene (PE) powder. Oscillations of electrical potential differences within the marble were recorded by inserting a pair of electrodes through the LM powder coating into the BZ solution core. Electrical potential differences of up to 100 mV were observed with an average period of oscillation ca 44 s. BZ LMs were subsequently frozen to -1°C to observe changes in the frequency of electrical potential oscillations. The frequency of oscillations reduced upon freezing to 11 mHz cf. 23 mHz at ambient temperature. The oscillation frequency of the frozen BZ LM returned to 23 mHz upon warming to ambient temperature. Several cycles of frequency fluctuations were able to be achieved.
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Affiliation(s)
- Andrew Adamatzky
- Unconventional Computing Laboratory, Department of Computer Science and Creative Technologies, Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
| | - Claire Fullarton
- Unconventional Computing Laboratory, Department of Computer Science and Creative Technologies, Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
| | - Neil Phillips
- Unconventional Computing Laboratory, Department of Computer Science and Creative Technologies, Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
| | - Ben De Lacy Costello
- Unconventional Computing Laboratory, Department of Computer Science and Creative Technologies, Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
- Institute of Biosensing Technology, Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
| | - Thomas C. Draper
- Unconventional Computing Laboratory, Department of Computer Science and Creative Technologies, Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
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