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Zhang Z, Wang Y, Zhang C, Zhan W, Zhang Q, Xue L, Xu Z, Peng N, Jiang Z, Ye Z, Liu M, Zhang X. Cilia-Inspired Magnetic Flexible Shear Force Sensors for Tactile and Fluid Monitoring. ACS APPLIED MATERIALS & INTERFACES 2024; 16:50524-50533. [PMID: 39266047 DOI: 10.1021/acsami.4c12957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/14/2024]
Abstract
Recently, there has been a burgeoning interest in flexible shear force sensors capable of precisely detecting both magnitude and direction. Despite considerable efforts, the challenge of achieving accurate direction recognition persists, primarily due to the inherent structural characteristics and sensing mechanisms. Here, we present a shear force sensor constructed by a magnetically induced assembled Ni/PDMS composite membrane, which is magnetized and integrated with a three-axis Hall sensor, facilitating its ability to simultaneously monitor both shear force magnitude (0.7-87 mN) and direction (0-360°). The cilia-inspired shear force magnetic sensor (CISFMS) exhibits admirable attributes, including exceptional flexibility, high sensitivity (0.76 mN-1), an exceedingly low detection limit (1° and 0.7 mN), and remarkable durability (over 10,000 bending cycles). Further, our results demonstrate the capacity of the CISFMS in detecting tactile properties, fluid velocity, and direction, offering substantial potential for future developments in wearable electronics.
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Affiliation(s)
- Zeying Zhang
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Engineering Research Center of Spin Quantum Sensor Chips, Universities of Shaanxi Province, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Yijing Wang
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
| | - Cuiling Zhang
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
| | - Wang Zhan
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
| | - Qi Zhang
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
| | - Li Xue
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
| | - Zhe Xu
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
| | - Niancai Peng
- State Key Laboratory for Manufacturing Systems Engineering, School of Instrument Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710054, P. R. China
| | - Zhuangde Jiang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 7100049, Shaanxi, P. R. China
| | - Zhilu Ye
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
| | - Ming Liu
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Engineering Research Center of Spin Quantum Sensor Chips, Universities of Shaanxi Province, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Xiaohui Zhang
- State Key Laboratory for Manufacturing Systems Engineering, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Center for Mitochondrial Biology and Medicine, School of Life Science and Technology, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Key Laboratory for Biomedical Testing and High-End Equipment, Xi'an Jiaotong University, Xi'an 710049, Shannxi, P. R. China
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Xiang X, Zhang K, Qin Y, Ma X, Dai Y, Zhang X, Niu W, He P. Smart Cushions with Machine Learning-Enhanced Force Sensors for Pressure Injury Risk Assessment. ACS APPLIED MATERIALS & INTERFACES 2024; 16:38466-38477. [PMID: 38995996 DOI: 10.1021/acsami.4c05964] [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: 07/14/2024]
Abstract
Prolonged sitting can easily result in pressure injury (PI) for certain people who have had strokes or spinal cord injuries. There are not many methods available for tracking contact surface pressure and shear force to evaluate the PI risk. Here, we propose a smart cushion that uses two-dimensional force sensors (2D-FSs) to measure the pressure and shear force in the buttocks. A machine learning algorithm is then used to compute the shear stresses in the gluteal muscles, which helps to determine the PI risk. The 2D-FS consists of a ferroelectret coaxial sensor (FCS) unit placed atop a ferroelectret film sensor (FFS) unit, allowing it to detect both vertical and horizontal forces simultaneously. To characterize and calibrate, two experimental approaches are applied: one involves simultaneously applying two perpendicular forces, and one involves applying a single force. To separate the two forces, the 2D-FS is decoupled using a deep neural network technique. Multiple FCSs are embedded to form a smart cushion, and a genetic algorithm-optimized backpropagation neural network is proposed and trained to predict the shear strain in the buttocks to prevent PI. By tracking the danger of PI, the smart cushion based on 2D-FSs may be further connected with home-based intelligent care platforms to increase patient equality for spinal cord injury patients and lower the expense of nursing or rehabilitation care.
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Affiliation(s)
- Xinhao Xiang
- Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 201619, China
| | - Ke Zhang
- Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 201619, China
- Department of Rehabilitation Sciences, School of Medicine, Tongji University, Shanghai 200092, China
| | - Yi Qin
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xingchen Ma
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Ying Dai
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai ,200092, China
| | - Xiaoqing Zhang
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Wenxin Niu
- Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 201619, China
- Department of Rehabilitation Sciences, School of Medicine, Tongji University, Shanghai 200092, China
| | - Pengfei He
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai ,200092, China
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Zhang J, Hou X, Qian S, Huo J, Yuan M, Duan Z, Song X, Wu H, Shi S, Geng W, Mu J, He J, Chou X. Flexible wide-range multidimensional force sensors inspired by bones embedded in muscle. MICROSYSTEMS & NANOENGINEERING 2024; 10:64. [PMID: 38784374 PMCID: PMC11111798 DOI: 10.1038/s41378-024-00711-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 01/15/2024] [Accepted: 02/10/2024] [Indexed: 05/25/2024]
Abstract
Flexible sensors have been widely studied for use in motion monitoring, human‒machine interactions (HMIs), personalized medicine, and soft intelligent robots. However, their practical application is limited by their low output performance, narrow measuring range, and unidirectional force detection. Here, to achieve flexibility and high performance simultaneously, we developed a flexible wide-range multidimensional force sensor (FWMFS) similar to bones embedded in muscle structures. The adjustable magnetic field endows the FWMFS with multidimensional perception for detecting forces in different directions. The multilayer stacked coils significantly improved the output from the μV to the mV level while ensuring FWMFS miniaturization. The optimized FWMFS exhibited a high voltage sensitivity of 0.227 mV/N (0.5-8.4 N) and 0.047 mV/N (8.4-60 N) in response to normal forces ranging from 0.5 N to 60 N and could detect lateral forces ranging from 0.2-1.1 N and voltage sensitivities of 1.039 mV/N (0.2-0.5 N) and 0.194 mV/N (0.5-1.1 N). In terms of normal force measurements, the FWMFS can monitor finger pressure and sliding trajectories in response to finger taps, as well as measure plantar pressure for assessing human movement. The plantar pressure signals of five human movements collected by the FWMFS were analyzed using the k-nearest neighbors classification algorithm, which achieved a recognition accuracy of 92%. Additionally, an artificial intelligence biometric authentication system is being developed that classifies and recognizes user passwords. Based on the lateral force measurement ability of the FWMFS, the direction of ball movement can be distinguished, and communication systems such as Morse Code can be expanded. This research has significant potential in intelligent sensing and personalized spatial recognition.
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Affiliation(s)
- Jie Zhang
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Xiaojuan Hou
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Shuo Qian
- School of Software, North University of China, Taiyuan, 030051 China
| | - Jiabing Huo
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Mengjiao Yuan
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Zhigang Duan
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Xiaoguang Song
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Hui Wu
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Shuzheng Shi
- School of Mechanical Engineering, Hebei University of Architecture, Zhangjiakou, 075000 China
- HBIS Group Co. Ltd., Shijiazhuang, 050023 China
| | - Wenping Geng
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Jiliang Mu
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Jian He
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
| | - Xiujian Chou
- Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, 030051 China
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Han C, Cao Z, Hu Y, Zhang Z, Li C, Wang ZL, Wu Z. Flexible Tactile Sensors for 3D Force Detection. NANO LETTERS 2024; 24:5277-5283. [PMID: 38624178 DOI: 10.1021/acs.nanolett.4c00894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
As tactile force sensing has become increasingly significant in the field of machine haptics, achieving multidimensional force sensing remains a challenge. We propose a 3D flexible force sensor that consists of an axisymmetric hemispherical protrusion and four equally sized quarter-circle electrodes. By simulating the device using a force and electrical field model, it has been found that the magnitude and direction of the force can be expressed through the voltage relationship of the four electrodes when the magnitude of the shear force remains constant and its direction varies within 0-360°. The experimental results show that a resolution of 15° can be achieved in the range 0-90°. Additionally, we installed the sensor on a robotic hand, enabling it to perceive the magnitude and direction of touch and grasp actions. Based on this, the designed 3D flexible tactile force sensor provides valuable insights for multidimensional force detection and applications.
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Affiliation(s)
- Chengcheng Han
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Zhi Cao
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yiran Hu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Zhiwei Zhang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chengyu Li
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Zhong Lin Wang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Zhiyi Wu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Zhang Y, Zeng J, Wang Y, Jiang G. Flexible Three-Dimensional Force Tactile Sensor Based on Velostat Piezoresistive Films. MICROMACHINES 2024; 15:486. [PMID: 38675297 PMCID: PMC11051711 DOI: 10.3390/mi15040486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 03/25/2024] [Accepted: 03/29/2024] [Indexed: 04/28/2024]
Abstract
The development of a high-performance, low-cost, and simply fabricated flexible three-dimensional (3D) force sensor is essential for the future development of electronic skins suitable for the detection of normal and shear forces for several human motions. In this study, a sandwich-structured flexible 3D force tactile sensor based on a polyethylene-carbon composite material (velostat) is presented. The sensor has a large measuring range, namely, 0-12 N in the direction of the normal force and 0-2.6 N in the direction of the shear force. For normal forces, the sensitivity is 0.775 N-1 at 0-1 N, 0.107 N-1 between 1 and 3 N, and 0.003 N-1 at 3 N and above. For shear forces, the measured sensitivity is 0.122 and 0.12 N-1 in x- and y-directions, respectively. Additionally, the sensor exhibits good repeatability and stability after 2500 cycles of loading and releasing. The response and recovery times of the sensor are as fast as 40 and 80 ms, respectively. Furthermore, we prepared a glove-like sensor array. When grasping the object using the tactile glove, the information about the force applied to the sensing unit can be transmitted through a wireless system in real-time and displayed on a personal computer (PC). The prepared flexible 3D force sensor shows broad application prospects in the field of smart wearable devices.
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Affiliation(s)
- Yuanxiang Zhang
- College of Mechanical Engineering, Quzhou University, Quzhou 324000, China; (J.Z.); (Y.W.); (G.J.)
| | - Jiantao Zeng
- College of Mechanical Engineering, Quzhou University, Quzhou 324000, China; (J.Z.); (Y.W.); (G.J.)
- College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Yong Wang
- College of Mechanical Engineering, Quzhou University, Quzhou 324000, China; (J.Z.); (Y.W.); (G.J.)
- College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Guoquan Jiang
- College of Mechanical Engineering, Quzhou University, Quzhou 324000, China; (J.Z.); (Y.W.); (G.J.)
- College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310023, China
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Park J, Lee Y, Cho S, Choe A, Yeom J, Ro YG, Kim J, Kang DH, Lee S, Ko H. Soft Sensors and Actuators for Wearable Human-Machine Interfaces. Chem Rev 2024; 124:1464-1534. [PMID: 38314694 DOI: 10.1021/acs.chemrev.3c00356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Haptic human-machine interfaces (HHMIs) combine tactile sensation and haptic feedback to allow humans to interact closely with machines and robots, providing immersive experiences and convenient lifestyles. Significant progress has been made in developing wearable sensors that accurately detect physical and electrophysiological stimuli with improved softness, functionality, reliability, and selectivity. In addition, soft actuating systems have been developed to provide high-quality haptic feedback by precisely controlling force, displacement, frequency, and spatial resolution. In this Review, we discuss the latest technological advances of soft sensors and actuators for the demonstration of wearable HHMIs. We particularly focus on highlighting material and structural approaches that enable desired sensing and feedback properties necessary for effective wearable HHMIs. Furthermore, promising practical applications of current HHMI technology in various areas such as the metaverse, robotics, and user-interactive devices are discussed in detail. Finally, this Review further concludes by discussing the outlook for next-generation HHMI technology.
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Affiliation(s)
- Jonghwa Park
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Youngoh Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Seungse Cho
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Ayoung Choe
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Jeonghee Yeom
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Yun Goo Ro
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Jinyoung Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Dong-Hee Kang
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Seungjae Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Hyunhyub Ko
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
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Tu X, Fang L, Zhang H, Wang Z, Chen C, Wang L, He W, Liu H, Wang P. Performance-Enhanced Flexible Self-Powered Tactile Sensor Arrays Based on Lotus Root-Derived Porous Carbon for Real-Time Human-Machine Interaction of the Robotic Snake. ACS APPLIED MATERIALS & INTERFACES 2024; 16:9333-9342. [PMID: 38345015 DOI: 10.1021/acsami.3c18714] [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: 02/23/2024]
Abstract
Flexible tactile sensors play an important role in the development of wearable electronics and human-machine interaction (HMI) systems. However, poor sensing abilities, an indispensable external energy supply, and limited material selection have significantly constrained their advancement. Herein, a self-powered flexible triboelectric sensor (TES) is proposed by integrating lotus-root-derived porous carbon (PC) into polydimethylsiloxane (PDMS). Owing to the superior charge capturing capability of PC, the PDMS/PC (PPC)-based TES exhibits an open-circuit voltage (Voc) of 22.8 V when it is periodically patted by skin at the pressure of 2 N and the frequency of 1 Hz, which is 5 times higher than that of a pristine PDMS-based TES. Furthermore, the as-prepared self-powered TES exhibits a high sensitivity of 3.24 V kPa-1 below 15 kPa for detecting human motion signals, such as finger clicks, joint bends, etc. Last but not the least, after the assembly of a PPC-based TES array and construction of an HMI system, the robotic snake can be controlled remotely by recognizing finger touching signals. This work shows broad potential applications for the self-powered TES in the fields of intelligent robotics, flexible electronics, disaster relief, and intelligence spying.
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Affiliation(s)
- Xinbo Tu
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
| | - Lin Fang
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
| | - Haonan Zhang
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
| | - Zixun Wang
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
| | - Chen Chen
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
| | - Longsen Wang
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
| | - Wen He
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
| | - Huawang Liu
- College of Artificial Intelligence, Nankai University, Tianjin 300071, China
| | - Peihong Wang
- School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China
- Hubei Key Laboratory of Electric Manufacturing and Packaging Integration (Wuhan University), Wuhan University, Wuhan, Hubei 430072, China
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Zhang H, Zhang Y. Rational Design of Flexible Mechanical Force Sensors for Healthcare and Diagnosis. MATERIALS (BASEL, SWITZERLAND) 2023; 17:123. [PMID: 38203977 PMCID: PMC10780056 DOI: 10.3390/ma17010123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/13/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024]
Abstract
Over the past decade, there has been a significant surge in interest in flexible mechanical force sensing devices and systems. Tremendous efforts have been devoted to the development of flexible mechanical force sensors for daily healthcare and medical diagnosis, driven by the increasing demand for wearable/portable devices in long-term healthcare and precision medicine. In this review, we summarize recent advances in diverse categories of flexible mechanical force sensors, covering piezoresistive, capacitive, piezoelectric, triboelectric, magnetoelastic, and other force sensors. This review focuses on their working principles, design strategies and applications in healthcare and diagnosis, with an emphasis on the interplay among the sensor architecture, performance, and application scenario. Finally, we provide perspectives on the remaining challenges and opportunities in this field, with particular discussions on problem-driven force sensor designs, as well as developments of novel sensor architectures and intelligent mechanical force sensing systems.
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Affiliation(s)
- Hang Zhang
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore;
| | - Yihui Zhang
- Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
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Ouyang W, Luo F, Yao Y, Qu B, Feng C, Xie Y, Chen B. A Triboelectric Sensor with Double Bubble Structure Applied in a High Security Double Lock System. ACS Sens 2023; 8:4615-4624. [PMID: 38063342 DOI: 10.1021/acssensors.3c01574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
With more attention on personal privacy and the need for a security defense, it is necessary to design an intelligent lock system with a higher security performance. Here, a novel high security double lock system integrating triboelectric nanogenerators (TENGs) with a double bubble structure (DB-TENG) and deep learning models is proposed. The TENG as a self-powered sensor is developed using silicone rubber and copper foil. By optimizing the thickness of the top layer film, surface microstructure, the size of the air bubble, and design of the double bubble structure, the sensitivity of the DB-TENG reaches 19.08 V/kPa. For the feasibility study, the sensor is fabricated to a smart belt to collect respiratory behaviors as a respiratory code. A Long Short-Term Memory network is adopted to identify four typical respiratory signals with an average accuracy of 97.00%. The system is deployed on a Raspberry Pi to determine whether the user is permitted through both the collected respiratory code and the related face image and will send an alarm message if one of the two does not match. It is worth mentioning that users can send alarm signals undiscovered by controlling their respiratory signals. Therefore, the proposed system has superb potential in security demanding environments.
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Affiliation(s)
- Wei Ouyang
- Chongqing Key Laboratory of Non-linear Circuit and Intelligent Information Processing, College of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
| | - Fangyuan Luo
- Chongqing Key Laboratory of Non-linear Circuit and Intelligent Information Processing, College of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
| | - Youbin Yao
- Chongqing Key Laboratory of Non-linear Circuit and Intelligent Information Processing, College of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
| | - Bingbing Qu
- Chongqing Key Laboratory of Non-linear Circuit and Intelligent Information Processing, College of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
| | - Changhao Feng
- Chongqing Key Laboratory of Non-linear Circuit and Intelligent Information Processing, College of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
| | - Yiyuan Xie
- Chongqing Key Laboratory of Non-linear Circuit and Intelligent Information Processing, College of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
| | - Bin Chen
- Chongqing Key Laboratory of Non-linear Circuit and Intelligent Information Processing, College of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
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10
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Zhang C, Zhang X, Zhang Q, Sang S, Ji J, Hao R, Liu Y. A BTO/PVDF/PDMS Piezoelectric Tangential and Normal Force Sensor Inspired by a Wind Chime. MICROMACHINES 2023; 14:1848. [PMID: 37893286 PMCID: PMC10608896 DOI: 10.3390/mi14101848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/24/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023]
Abstract
There is a growing demand for flexible pressure sensors in environmental monitoring and human-robot interaction robotics. A flexible and susceptible sensor can discriminate multidirectional pressure, thus effectively detecting signals of small environmental changes and providing solutions for personalized medicine. This paper proposes a multidimensional force detection sensor inspired by a wind chime structure with a three-dimensional force structure to detect and analyze normal and shear forces in real time. The force-sensing structure of the sensor consists of an upper and lower membrane on a polydimethylsiloxane substrate and four surrounding cylinders. A piezoelectric hemisphere is made of BTO/PVDF/PDMS composite material. The sensor columns in the wind chime structure surround the piezoelectric layer in the middle. When pressure is applied externally, the sensor columns are connected to the piezoelectric layer with a light touch. The piezoelectric hemisphere generates a voltage signal. Due to the particular structure of the sensor, it can accurately capture multidimensional forces and identify the direction of the external force by analyzing the position of the sensor and the output voltage amplitude. The development of such sensors shows excellent potential for self-powered wearable sensors, human-computer interaction, electronic skin, and soft robotics applications.
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Affiliation(s)
- Chunyan Zhang
- Shanxi Key Laboratory of Micro Nano Sensors & Artificial Intelligence Perception, College of Electronic Information and Optical Engineering, Taiyuan University of Technology, Taiyuan 030024, China; (C.Z.); (Q.Z.); (S.S.); (J.J.); (R.H.)
- School of Software, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xiaotian Zhang
- School of Electronic Information, Hangzhou Dianzi University, Hangzhou 310018, China;
| | - Qiang Zhang
- Shanxi Key Laboratory of Micro Nano Sensors & Artificial Intelligence Perception, College of Electronic Information and Optical Engineering, Taiyuan University of Technology, Taiyuan 030024, China; (C.Z.); (Q.Z.); (S.S.); (J.J.); (R.H.)
- Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Shengbo Sang
- Shanxi Key Laboratory of Micro Nano Sensors & Artificial Intelligence Perception, College of Electronic Information and Optical Engineering, Taiyuan University of Technology, Taiyuan 030024, China; (C.Z.); (Q.Z.); (S.S.); (J.J.); (R.H.)
- Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Jianlong Ji
- Shanxi Key Laboratory of Micro Nano Sensors & Artificial Intelligence Perception, College of Electronic Information and Optical Engineering, Taiyuan University of Technology, Taiyuan 030024, China; (C.Z.); (Q.Z.); (S.S.); (J.J.); (R.H.)
- Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Runfang Hao
- Shanxi Key Laboratory of Micro Nano Sensors & Artificial Intelligence Perception, College of Electronic Information and Optical Engineering, Taiyuan University of Technology, Taiyuan 030024, China; (C.Z.); (Q.Z.); (S.S.); (J.J.); (R.H.)
- Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yan Liu
- School of Software, Taiyuan University of Technology, Taiyuan 030024, China
- Shanxi Research Institute of 6D Artificial Intelligence Biomedical Science, Taiyuan 030031, China
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11
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Xu J, Pan J, Cui T, Zhang S, Yang Y, Ren TL. Recent Progress of Tactile and Force Sensors for Human-Machine Interaction. SENSORS (BASEL, SWITZERLAND) 2023; 23:1868. [PMID: 36850470 PMCID: PMC9961639 DOI: 10.3390/s23041868] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/23/2023] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Human-Machine Interface (HMI) plays a key role in the interaction between people and machines, which allows people to easily and intuitively control the machine and immersively experience the virtual world of the meta-universe by virtual reality/augmented reality (VR/AR) technology. Currently, wearable skin-integrated tactile and force sensors are widely used in immersive human-machine interactions due to their ultra-thin, ultra-soft, conformal characteristics. In this paper, the recent progress of tactile and force sensors used in HMI are reviewed, including piezoresistive, capacitive, piezoelectric, triboelectric, and other sensors. Then, this paper discusses how to improve the performance of tactile and force sensors for HMI. Next, this paper summarizes the HMI for dexterous robotic manipulation and VR/AR applications. Finally, this paper summarizes and proposes the future development trend of HMI.
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Affiliation(s)
- Jiandong Xu
- School of Integrated Circuits and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Jiong Pan
- School of Integrated Circuits and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Tianrui Cui
- School of Integrated Circuits and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Sheng Zhang
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Yi Yang
- School of Integrated Circuits and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Tian-Ling Ren
- School of Integrated Circuits and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
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12
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Watanabe H, Sasaki K, Terada T, Tsukamoto M. Method for Recognizing Pressing Position and Shear Force Using Active Acoustic Sensing on Gel Plates. SENSORS (BASEL, SWITZERLAND) 2022; 22:9951. [PMID: 36560320 PMCID: PMC9784324 DOI: 10.3390/s22249951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/10/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
A touch interface is an important technology used in many devices, including touch panels in smartphones. Many touch panels only detect the contact position. If devices can detect shear force in addition to the contact position, various touch interactions are possible. We propose a two-step recognition method for recognizing the pressing position and shear force using active acoustic sensing, which transmits acoustic signals to an object and recognizes the state of the object by analyzing its response. Specifically, we attach a contact speaker transmitting an ultrasonic sweep signal and a contact microphone receiving ultrasonic waves to a plate of gel. The propagation characteristics of ultrasonic waves differ due to changes in the shape of the gel caused by the user's actions on the gel. This system recognizes the pressing position and shear force on the basis of the difference in acoustic characteristics. An evaluation of our method involving a user-independent model confirmed that four pressing positions were recognized with an F1 score of 85.4%, and four shear-force directions were recognized with an F1 score of 69.4%.
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Affiliation(s)
- Hiroki Watanabe
- Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814, Japan
| | - Kaito Sasaki
- Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
| | - Tsutomu Terada
- Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
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Chen Z, Gao F, Liang J. Kinetic energy harvesting based sensing and IoT systems: A review. FRONTIERS IN ELECTRONICS 2022. [DOI: 10.3389/felec.2022.1017511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The rapid advance of the Internet of Things (IoT) has attracted growing interest in academia and industry toward pervasive sensing and everlasting IoT. As the IoT nodes exponentially increase, replacing and recharging their batteries proves an incredible waste of labor and resources. Kinetic energy harvesting (KEH), converting the wasted ambient kinetic energy into usable electrical energy, is an emerging research field where various working mechanisms and designs have been developed for improved performance. Leveraging the KEH technologies, many motion-powered sensors, where changes in the external environment are directly converted into corresponding self-generated electrical signals, are developed and prove promising for multiple self-sensing applications. Furthermore, some recent studies focus on utilizing the generated energy to power a whole IoT sensing system. These systems comprehensively consider the mechanical, electrical, and cyber parts, which lead a further step to truly self-sustaining and maintenance-free IoT systems. Here, this review starts with a brief introduction of KEH from the ambient environment and human motion. Furthermore, the cutting-edge KEH-based sensors are reviewed in detail. Subsequently, divided into two aspects, KEH-based battery-free sensing systems toward IoT are highlighted. Moreover, there are remarks in every chapter for summarizing. The concept of self-powered sensing is clarified, and advanced studies of KEH-based sensing in different fields are introduced. It is expected that this review can provide valuable references for future pervasive sensing and ubiquitous IoT.
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14
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Zhu M, Sun Z, Lee C. Soft Modular Glove with Multimodal Sensing and Augmented Haptic Feedback Enabled by Materials' Multifunctionalities. ACS NANO 2022; 16:14097-14110. [PMID: 35998364 DOI: 10.1021/acsnano.2c04043] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Immersive communications rely on smart perception based on diversified and augmented sensing and feedback technologies. However, the increasing of functional components also raises the issue of increased system complexity. Here, we propose a modular soft glove with multimodal sensing and feedback functions by exploring and utilizing the multiple properties of glove materials. With a single design of basic structure, the main functional unit possesses triboelectric-based sensing of static and dynamic contact, vibration, strain, and pneumatic actuation. Additionally, the same unit is also capable of offering pneumatic tactile haptic feedback and electroresistive thermal haptic feedback. Together with a machine learning algorithm, the proposed glove not only performs real-time detection of dexterous hand motion and direct feedback but also realizes intelligent object recognition and augmented feedback, which significantly enhance the communication and perception of more comprehensive information. In general, this glove utilizes a facile designed sensing and feedback device to achieve dual-way and multimodal communication among humans, machines, and the virtual world via smart perceptions.
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Affiliation(s)
- Minglu Zhu
- Department of Electrical & Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore
- Center for Sensors and MEMS, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore
- National University of Singapore Suzhou Research Institute (NUSRI), Suzhou Industrial Park, Suzhou 215123, China
- Jiangsu Provincial Key Laboratory of Advanced Robotics, School of Mechanical and Electric Engineering, Soochow University, Suzhou 215123, China
| | - Zhongda Sun
- Department of Electrical & Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore
- Center for Sensors and MEMS, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore
| | - Chengkuo Lee
- Department of Electrical & Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore
- Center for Sensors and MEMS, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore
- National University of Singapore Suzhou Research Institute (NUSRI), Suzhou Industrial Park, Suzhou 215123, China
- NUS Graduate School-Integrative Sciences and Engineering Program (ISEP), National University of Singapore, Singapore 119077, Singapore
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15
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Nan X, Wang X, Kang T, Zhang J, Dong L, Dong J, Xia P, Wei D. Review of Flexible Wearable Sensor Devices for Biomedical Application. MICROMACHINES 2022; 13:1395. [PMID: 36144018 PMCID: PMC9505309 DOI: 10.3390/mi13091395] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 05/26/2023]
Abstract
With the development of cross-fertilisation in various disciplines, flexible wearable sensing technologies have emerged, bringing together many disciplines, such as biomedicine, materials science, control science, and communication technology. Over the past few years, the development of multiple types of flexible wearable devices that are widely used for the detection of human physiological signals has proven that flexible wearable devices have strong biocompatibility and a great potential for further development. These include electronic skin patches, soft robots, bio-batteries, and personalised medical devices. In this review, we present an updated overview of emerging flexible wearable sensor devices for biomedical applications and a comprehensive summary of the research progress and potential of flexible sensors. First, we describe the selection and fabrication of flexible materials and their excellent electrochemical properties. We evaluate the mechanisms by which these sensor devices work, and then we categorise and compare the unique advantages of a variety of sensor devices from the perspective of in vitro and in vivo sensing, as well as some exciting applications in the human body. Finally, we summarise the opportunities and challenges in the field of flexible wearable devices.
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Affiliation(s)
- Xueli Nan
- School of Automation and Software Engineering, Shanxi University, Taiyuan 030006, China
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Xin Wang
- School of Automation and Software Engineering, Shanxi University, Taiyuan 030006, China
| | - Tongtong Kang
- School of Automation and Software Engineering, Shanxi University, Taiyuan 030006, China
| | - Jiale Zhang
- School of Automation and Software Engineering, Shanxi University, Taiyuan 030006, China
| | - Lanxiao Dong
- School of Automation and Software Engineering, Shanxi University, Taiyuan 030006, China
| | - Jinfeng Dong
- School of Automation and Software Engineering, Shanxi University, Taiyuan 030006, China
| | - Peng Xia
- School of Mathematical Sciences, Shanxi University, Taiyuan 030006, China
| | - Donglai Wei
- School of Mathematical Sciences, Shanxi University, Taiyuan 030006, China
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16
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Xu W, Li X, Chen R, Lin W, Yuan D, Geng D, Luo T, Zhang J, Wu L, Zhou W. Ordered Magnetic Cilia Array Induced by the Micro-cavity Effect for the In Situ Adjustable Pressure Sensor. ACS APPLIED MATERIALS & INTERFACES 2022; 14:38291-38301. [PMID: 35971645 DOI: 10.1021/acsami.2c08124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Cilia are fundamental functional structures in natural biology. As the primary option of artificial cilia, magnetic cilia have been drawing extensive attention due to their excellent biocompatibility, sensitive response, and contactless actuation. However, most of the ordered magnetic cilia are fabricated by molds, suffering from high cost and low efficiency. In this paper, an ultrafast fabrication method of ordered cilia array using the micro-cavity inducing effect was proposed. With the impact of static and dynamic magnetic fields, the fine cilia were first formed in out-cavity area and then converged above cavities forming complete cilia structures. The mechanism of the micro-cavity inducing effect was further revealed. Finally, the ordered cilia array was used to develop the pressure sensor with variable stiffness, making the in situ adjustment of the sensor performance possible. The ordered cilia array was applied as a micro-mixer and largely improved the mixing efficiency for different mediums. The ordered cilia array also successfully served as the info carrier for rapid sub-encryption. This method allows the fast and controlled forming of ordered cilia arrays within 30 s, and the cilia structure can be adjusted in a large range of aspect ratios (1-9), providing an approach to large-scale producing the magnetic cilia for different applications.
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Affiliation(s)
- Wenjun Xu
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Xinying Li
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Rui Chen
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Weiming Lin
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Ding Yuan
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Da Geng
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Tao Luo
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Jinhui Zhang
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Linjing Wu
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
| | - Wei Zhou
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen 361101, P. R. China
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