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Geng B, Zeng H, Luo H, Wu X. Construction of Wearable Touch Sensors by Mimicking the Properties of Materials and Structures in Nature. Biomimetics (Basel) 2023; 8:372. [PMID: 37622977 PMCID: PMC10452172 DOI: 10.3390/biomimetics8040372] [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: 07/25/2023] [Revised: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 08/26/2023] Open
Abstract
Wearable touch sensors, which can convert force or pressure signals into quantitative electronic signals, have emerged as essential smart sensing devices and play an important role in various cutting-edge fields, including wearable health monitoring, soft robots, electronic skin, artificial prosthetics, AR/VR, and the Internet of Things. Flexible touch sensors have made significant advancements, while the construction of novel touch sensors by mimicking the unique properties of biological materials and biogenetic structures always remains a hot research topic and significant technological pathway. This review provides a comprehensive summary of the research status of wearable touch sensors constructed by imitating the material and structural characteristics in nature and summarizes the scientific challenges and development tendencies of this aspect. First, the research status for constructing flexible touch sensors based on biomimetic materials is summarized, including hydrogel materials, self-healing materials, and other bio-inspired or biomimetic materials with extraordinary properties. Then, the design and fabrication of flexible touch sensors based on bionic structures for performance enhancement are fully discussed. These bionic structures include special structures in plants, special structures in insects/animals, and special structures in the human body. Moreover, a summary of the current issues and future prospects for developing wearable sensors based on bio-inspired materials and structures is discussed.
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Affiliation(s)
| | | | - Hua Luo
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
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Duan S, Lin Y, Wang Z, Tang J, Li Y, Zhu D, Wu J, Tao L, Choi CH, Sun L, Xia J, Wei L, Wang B. Conductive Porous MXene for Bionic, Wearable, and Precise Gesture Motion Sensors. RESEARCH (WASHINGTON, D.C.) 2021; 2021:9861467. [PMID: 34223178 PMCID: PMC8212815 DOI: 10.34133/2021/9861467] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/23/2021] [Indexed: 01/19/2023]
Abstract
Reliable, wide range, and highly sensitive joint movement monitoring is essential for training activities, human behavior analysis, and human-machine interfaces. Yet, most current motion sensors work on the nano/microcracks induced by the tensile deformation on the convex surface of joints during joint movements, which cannot satisfy requirements of ultrawide detectable angle range, high angle sensitivity, conformability, and consistence under cyclic movements. In nature, scorpions sense small vibrations by allowing for compression strain conversion from external mechanical vibrations through crack-shaped slit sensilla. Here, we demonstrated that ultraconformal sensors based on controlled slit structures, inspired by the geometry of a scorpion's slit sensilla, exhibit high sensitivity (0.45%deg-1), ultralow angle detection threshold (~15°), fast response/relaxation times (115/72 ms), wide range (15° ~120°), and durability (over 1000 cycles). Also, a user-friendly, hybrid sign language system has been developed to realize Chinese and American sign language recognition and feedback through video and speech broadcasts, making these conformal motion sensors promising candidates for joint movement monitoring in wearable electronics and robotics technology.
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Affiliation(s)
- Shengshun Duan
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Yucheng Lin
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Zhehan Wang
- School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
- Center for 2D Materials, Southeast University, Nanjing 211189, China
| | - Junyi Tang
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Yinhui Li
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Di Zhu
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Jun Wu
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Li Tao
- School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
- Center for 2D Materials, Southeast University, Nanjing 211189, China
- Center for Advanced Materials and Manufacture, Joint Research Institute of Southeast University and Monash University, Suzhou 215123, China
| | - Chang-Hwan Choi
- Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
| | - Litao Sun
- Center for 2D Materials, Southeast University, Nanjing 211189, China
- Center for Advanced Materials and Manufacture, Joint Research Institute of Southeast University and Monash University, Suzhou 215123, China
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education Collaborative Innovation Center for Micro/Nano Fabrication Device and System, Southeast University, Nanjing 210096, China
- Center for Advanced Carbon Materials, Southeast University and Jiangnan Graphene Research Institute, Changzhou 213100, China
| | - Jun Xia
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Lei Wei
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
| | - Baoping Wang
- Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China
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Blickhan R, Weihmann T, Barth FG. Measuring strain in the exoskeleton of spiders-virtues and caveats. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2021; 207:191-204. [PMID: 33459819 PMCID: PMC8046692 DOI: 10.1007/s00359-020-01458-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/05/2020] [Accepted: 12/08/2020] [Indexed: 11/23/2022]
Abstract
The measurement of cuticular strain during locomotion using foil strain gauges provides information both on the loads of the exoskeleton bears and the adaptive value of the specific location of natural strain detectors (slit sense organs). Here, we critically review available literature. In tethered animals, by applying loads to the metatarsus tip, strain and mechanical sensitivity (S = strain/load) induced at various sites in the tibia were determined. The loci of the lyriform organs close to the tibia-metatarsus joint did not stand out by high strain. The strains induced at various sites during free locomotion can be interpreted based on S and, beyond the joint region, on beam theory. Spiders avoided laterad loading of the tibia-metatarsus joint during slow locomotion. Balancing body weight, joint flexors caused compressive strain at the posterior and dorsal tibia. While climbing upside down strain measurements indicate strong flexor activity. In future studies, a precise calculation and quantitative determination of strain at the sites of the lyriform organs will profit from more detailed data on the overall strain distribution, morphology, and material properties. The values and caveats of the strain gauge technology, the only one applicable to freely moving spiders, are discussed.
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Affiliation(s)
- Reinhard Blickhan
- Science of Motion, Friedrich Schiller-University, Seidelstr. 20, 00749 Jena, Germany
| | - Tom Weihmann
- Institute of Zoology, University of Cologne, Zülpicher Str. 47b, 50674 Köln, Germany
| | - Friedrich G. Barth
- Department of Neuroscience and Developmental Biology, University of Vienna, Althanstr. 14, 1090 Wien, Austria
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Miller TE, Mortimer B. Control vs. Constraint: Understanding the Mechanisms of Vibration Transmission During Material-Bound Information Transfer. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.587846] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Material-bound vibrations are ubiquitous in the environment and are widely used as an information source by animals, whether they are generated by biotic or abiotic sources. The process of vibration information transfer is subject to a wide range of physical constraints, especially during the vibration transmission phase. This is because vibrations must travel through materials in the environment and body of the animal before reaching embedded mechanosensors. Morphology therefore plays a key and often overlooked role in shaping information flow. Web-building spiders are ideal organisms for studying vibration information transfer due to the level of control they have over morphological traits, both within the web (environment) and body, which can give insights for bioinspired design. Here we investigate the mechanisms governing vibration information transfer, including the relative roles of constraints and control mechanisms. We review the known and theoretical contributions of morphological and behavioral traits to vibration transmission in these spiders, and propose an interdisciplinary framework for considering the effects of these traits from a biomechanical perspective. Whereas morphological traits act as a series of springs, dampers and masses arranged in a specific geometry to influence vibration transmission, behavioral traits influence these morphologies often over small timescales in response to changing conditions. We then explore the relative roles of constraints and control mechanisms in shaping the variation of these traits at various taxonomic levels. This analysis reveals the importance of morphology modification to gain control over vibration transmission to mitigate constraints and essentially promote information transfer. In particular, we hypothesize that morphological computation is used by spiders during vibration information transfer to reduce the amount of processing required by the central nervous system (CNS); a hypothesis that can be tested experimentally in the future. We can take inspiration from how spiders control vibration transmission and apply these insights to bioinspired engineering. In particular, the role of morphological computation for vibration control could open up potential developments for soft robots, which could use multi-scale vibration sensory systems inspired by spiders to quickly and efficiently adapt to changing environments.
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Kedambaimoole V, Kumar N, Shirhatti V, Nuthalapati S, Sen P, Nayak MM, Rajanna K, Kumar S. Laser-Induced Direct Patterning of Free-standing Ti 3C 2-MXene Films for Skin Conformal Tattoo Sensors. ACS Sens 2020; 5:2086-2095. [PMID: 32551595 DOI: 10.1021/acssensors.0c00647] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The discovery of stable two-dimensional (2D) materials has effectuated a rapid evolution of skin conformal sensors for health monitoring via epidermal electronics. Among the newly discovered 2D materials, MXene stands out as a solution-processable 2D material allowing easy fabrication of highly conductive thin films with the potential to realize flexible skin conformal sensors. Here, we present a successful demonstration of a Ti3C2-MXene resistor as an extremely sensitive strain sensor in the form an ultrathin skin mountable temporary tattoo. The skin conformability and form factor afforded by the sensor promises inconspicuous and continuous monitoring of vital health parameters of an individual, like the pulse rate, respiration rate, and surface electromyography. The sensor serves as a single conduit for sensing the respiration rate and pulse, dispensing with the need of mounting multiple sensors. Its remarkably high sensitivity with a gauge factor of ∼7400 has been ascribed to development of nanocracks and their propagation through the film upon application of strain. The fast response and highly repeatable sensor follows easy fabrication steps and can be patterned into any shape and size using a laser.
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Affiliation(s)
- Vaishakh Kedambaimoole
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bengaluru 560012, India
| | - Neelotpala Kumar
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bengaluru 560012, India
| | - Vijay Shirhatti
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bengaluru 560012, India
| | - Suresh Nuthalapati
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bengaluru 560012, India
| | - Prosenjit Sen
- Centre for Nano Science and Engineering (CeNSE), Indian Institute of Science, Bengaluru 560012, India
| | | | - Konandur Rajanna
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bengaluru 560012, India
| | - Saurabh Kumar
- Centre for Nano Science and Engineering (CeNSE), Indian Institute of Science, Bengaluru 560012, India
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6
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Liu YF, Liu Q, Li YQ, Huang P, Yao JY, Hu N, Fu SY. Spider-Inspired Ultrasensitive Flexible Vibration Sensor for Multifunctional Sensing. ACS APPLIED MATERIALS & INTERFACES 2020; 12:30871-30881. [PMID: 32520521 DOI: 10.1021/acsami.0c08884] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Flexible vibration sensors can not only capture broad classes of physiologically relevant information, including mechano-vibration signatures of body processes and precision kinematics of core-body motions, but also detect environmental seismic waves, providing early warning to wearers in time. Spider is one of the most vibration-sensitive creatures because of its hairlike sensilla and lyriform slit structure. Here, a spider-inspired ultrasensitive flexible vibration sensor is designed and fabricated for multifunctional sensing. The vibration sensitivity of the flexible sensor is increased over 2 orders of magnitude from 0.006 to 0.5 mV/g, and the strain sensitivity is hugely enhanced from 0.08 to 150 compared to a plain sensor counterpart. It is shown that the synergistic effect of cilium arrays and cracks is the key for achieving the greatly enhanced vibration and strain sensitivity. The dynamic sensitivity of 0.5 mV/g outperforms the corresponding commercial vibration sensors. The flexible sensor is demonstrated to be generally feasible for detecting vibration signals caused by walk, tumble, and explosion as well as capturing human body motions, indicating its great potential for applications in human health-monitoring devices, posture control in robotics, early earthquake warning, and so forth.
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Affiliation(s)
- Ya-Feng Liu
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
- Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Qun Liu
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
| | - Yuan-Qing Li
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
- State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400044, China
| | - Pei Huang
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
- State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400044, China
| | - Jian-Yao Yao
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
| | - Ning Hu
- School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China
- State Key Laboratory of Reliability and Intelligence Electrical Equipment, Hebei University of Technology, Tianjin 300401, China
| | - Shao-Yun Fu
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
- State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400044, China
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Mechanics to pre-process information for the fine tuning of mechanoreceptors. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:661-686. [PMID: 31270587 PMCID: PMC6726712 DOI: 10.1007/s00359-019-01355-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 11/17/2022]
Abstract
Non-nervous auxiliary structures play a significant role in sensory biology. They filter the stimulus and transform it in a way that fits the animal’s needs, thereby contributing to the avoidance of the central nervous system’s overload with meaningless stimuli and a corresponding processing task. The present review deals with mechanoreceptors mainly of invertebrates and some remarkable recent findings stressing the role of mechanics as an important source of sensor adaptedness, outstanding performance, and diversity. Instead of organizing the review along the types of stimulus energy (force) taken up by the sensors, processes associated with a few basic and seemingly simple mechanical principles like lever systems, viscoelasticity, resonance, traveling waves, and impedance matching are taken as the guideline. As will be seen, nature makes surprisingly competent use of such “simple mechanics”.
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Yin F, Yang J, Ji P, Peng H, Tang Y, Yuan W. Bioinspired Pretextured Reduced Graphene Oxide Patterns with Multiscale Topographies for High-Performance Mechanosensors. ACS APPLIED MATERIALS & INTERFACES 2019; 11:18645-18653. [PMID: 31042350 DOI: 10.1021/acsami.9b04509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Highly sensitive mechanical sensing is vital for the emerging field of skin mimicry and wearable healthcare systems. To date, it remains a big challenge to fabricate mechanosensors with both high sensitivity and a wide sensing range. In nature, slit sensilla are crack-shaped sensory organs of arachnids, which are highly sensitive to tiny external mechanical stimuli. Here, inspired by the geometry of slit sensilla, a concept is developed that pretextures reduced graphene oxide (RGO) nanocoating into multiscale topographies with agminated crumples and interlaced cracks (crumpled & cracked RGO) through an efficient and scalable mechanically driven process. Both the sensitivity and the workable range can be facilely tuned by adjusting the crack density. The resulting mechanosensor exhibits a comprehensive superior performance including high sensitivity (a gauge factor of 205 to 3256), a wide and tunable sensing range (from 0-40 to 0-180%), long-term stability (over 5000 cycles), and multiple sensing functions. Based on its excellent performances, the mechanosensor can be used as a wearable electronic to in situ monitor subtle physiological signals and vigorous body actions. The rationally designed crumpled & cracked RGO provides a promising platform for artificial electronic skin and portable healthcare systems.
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Affiliation(s)
- Fuxing Yin
- School of Materials Science & Engineering and Research Institute for Energy Equipment Materials , Hebei University of Technology , Tianjin 300130 , China
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology , Tianjin 300130 , China
| | - Jinzheng Yang
- School of Materials Science & Engineering and Research Institute for Energy Equipment Materials , Hebei University of Technology , Tianjin 300130 , China
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology , Tianjin 300130 , China
| | - Puguang Ji
- School of Materials Science & Engineering and Research Institute for Energy Equipment Materials , Hebei University of Technology , Tianjin 300130 , China
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology , Tianjin 300130 , China
| | - Huifen Peng
- School of Materials Science & Engineering and Research Institute for Energy Equipment Materials , Hebei University of Technology , Tianjin 300130 , China
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology , Tianjin 300130 , China
| | - Yanting Tang
- School of Materials Science & Engineering and Research Institute for Energy Equipment Materials , Hebei University of Technology , Tianjin 300130 , China
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology , Tianjin 300130 , China
| | - Wenjing Yuan
- School of Materials Science & Engineering and Research Institute for Energy Equipment Materials , Hebei University of Technology , Tianjin 300130 , China
- Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology , Tianjin 300130 , China
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Song H, Zhang J, Chen D, Wang K, Niu S, Han Z, Ren L. Superfast and high-sensitivity printable strain sensors with bioinspired micron-scale cracks. NANOSCALE 2017; 9:1166-1173. [PMID: 28009874 DOI: 10.1039/c6nr07333f] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Functional electronics has promising applications, including highly advanced human-interactive devices and healthcare monitoring. Here, we present a unique printable micron-scale cracked strain sensor (PMSCSS), which is bioinspired by a spider's crack-shaped lyriform slit organ. The PMSCSS is fabricated by a facile process that utilizes screen-printing to coat carbon black (CB) ink onto a paper substrate. With a certain bending radius, a cracked morphology emerged on the solidified ink layer. The working principle of the PMSCSS is prominently attributed to the strain-dependent variation in resistance due to the reconnection-disconnection of the crack fracture surfaces. The device shows appealing performances, with superfast response times (∼0.625 ms) and high sensitivity (gauge factor = 647). The response time surpasses most recent reports, and the sensitivity is comparable. We demonstrate the application of the PMSCSSs as encoders, which have good linearity and negligible hysteresis. Also, the sensor can be manipulated as a vibration detector by monitoring human-motion disturbances. According to the sensory information, some details of movements can be deduced.
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Affiliation(s)
- Honglie Song
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, P. R. China.
| | - Junqiu Zhang
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, P. R. China.
| | - Daobing Chen
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, P. R. China.
| | - Kejun Wang
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, P. R. China.
| | - Shichao Niu
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, P. R. China.
| | - Zhiwu Han
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, P. R. China.
| | - Luquan Ren
- Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, P. R. China.
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10
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Morley EL, Sivalinghem S, Mason AC. Developmental morphology of a lyriform organ in the Western black widow (Latrodectus hesperus). ZOOMORPHOLOGY 2016. [DOI: 10.1007/s00435-016-0324-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Kang D, Pikhitsa PV, Choi YW, Lee C, Shin SS, Piao L, Park B, Suh KY, Kim TI, Choi M. Ultrasensitive mechanical crack-based sensor inspired by the spider sensory system. Nature 2015; 516:222-6. [PMID: 25503234 DOI: 10.1038/nature14002] [Citation(s) in RCA: 566] [Impact Index Per Article: 62.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 10/13/2014] [Indexed: 12/12/2022]
Abstract
Recently developed flexible mechanosensors based on inorganic silicon, organic semiconductors, carbon nanotubes, graphene platelets, pressure-sensitive rubber and self-powered devices are highly sensitive and can be applied to human skin. However, the development of a multifunctional sensor satisfying the requirements of ultrahigh mechanosensitivity, flexibility and durability remains a challenge. In nature, spiders sense extremely small variations in mechanical stress using crack-shaped slit organs near their leg joints. Here we demonstrate that sensors based on nanoscale crack junctions and inspired by the geometry of a spider's slit organ can attain ultrahigh sensitivity and serve multiple purposes. The sensors are sensitive to strain (with a gauge factor of over 2,000 in the 0-2 per cent strain range) and vibration (with the ability to detect amplitudes of approximately 10 nanometres). The device is reversible, reproducible, durable and mechanically flexible, and can thus be easily mounted on human skin as an electronic multipixel array. The ultrahigh mechanosensitivity is attributed to the disconnection-reconnection process undergone by the zip-like nanoscale crack junctions under strain or vibration. The proposed theoretical model is consistent with experimental data that we report here. We also demonstrate that sensors based on nanoscale crack junctions are applicable to highly selective speech pattern recognition and the detection of physiological signals. The nanoscale crack junction-based sensory system could be useful in diverse applications requiring ultrahigh displacement sensitivity.
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Affiliation(s)
- Daeshik Kang
- 1] Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea [2] Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea
| | - Peter V Pikhitsa
- Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea
| | - Yong Whan Choi
- Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea
| | - Chanseok Lee
- Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea
| | - Sung Soo Shin
- Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea
| | - Linfeng Piao
- Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea
| | - Byeonghak Park
- 1] Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 440-746, South Korea [2] School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 440-746, South Korea
| | - Kahp-Yang Suh
- 1] Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea [2] Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea [3] Interdisciplinary Program of Bioengineering, Seoul National University, Seoul 151-742, South Korea
| | - Tae-il Kim
- 1] Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 440-746, South Korea [2] School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 440-746, South Korea
| | - Mansoo Choi
- 1] Global Frontier Center for Multiscale Energy Systems, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea [2] Division of WCU Multiscale Mechanical Design, Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, South Korea
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Vincent JF. Unusual uses of holes—With input from biology. J Mech Behav Biomed Mater 2011; 4:682-7. [DOI: 10.1016/j.jmbbm.2010.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 10/01/2010] [Accepted: 10/09/2010] [Indexed: 10/18/2022]
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Abstract
Living organisms use composite materials for various functions, such as mechanical support, protection, motility and the sensing of signals. Although the individual components of these materials may have poor mechanical qualities, they form composites of polymers and minerals with a remarkable variety of functional properties. Researchers are now using these natural systems as models for artificial mechanosensors and actuators, through studying both natural structures and their interactions with the environment. In addition to inspiring the design of new materials, analysis of natural structures on this basis can provide insight into evolutionary constraints on structure-function relationships in living organisms and the variety of structural solutions that emerged from these constraints.
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15
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Finite element modeling of arachnid slit sensilla: II. Actual lyriform organs and the face deformations of the individual slits. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2009; 195:881-94. [PMID: 19685059 DOI: 10.1007/s00359-009-0467-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/21/2009] [Accepted: 07/23/2009] [Indexed: 10/20/2022]
Abstract
Arachnid slit sensilla respond to minute strains in the exoskeleton. After having applied finite element (FE) analysis to simplified arrays of five straight slits (Hössl et al. J Comp Physiol A 193:445-459, 2007) we now present a computational study of the effects of more subtle natural variations in geometry, number and arrangement of slits on the slit face deformations. Our simulations show that even minor variations in these parameters can substantially influence a slit's directional response. Using white-light interferometric measurements of the surface deformations of a lyriform organ, it is shown that planar FE models are capable of predicting the principal characteristics of the mechanical responses. The magnitudes of the measured and calculated slit face deformations are in good agreement. At threshold, they measure between 1.7 and 43 nm. In a lyriform organ and a closely positioned loose group of slits, the detectable range of loads increases to approximately 3.5 times the range of the lyriform organ alone. Stress concentration factors (up to ca. 29) found in the vicinity of the slits were evaluated from the models. They are mitigated due to local thickening of the exocuticle and the arrangement of the chitinous microfibers that prevents the formation of cracks under physiological loading conditions.
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Hössl B, Böhm HJ, Rammerstorfer FG, Barth FG. Finite element modeling of arachnid slit sensilla-I. The mechanical significance of different slit arrays. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2006; 193:445-59. [PMID: 17186249 DOI: 10.1007/s00359-006-0201-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 11/09/2006] [Accepted: 11/27/2006] [Indexed: 10/23/2022]
Abstract
Arachnid strain sensitive slit sensilla are elongated openings in the cuticle with aspect ratios (slit length l/slit width b) of up to 100. Planar Finite Element (FE) models are used to calculate the relative slit face displacements, Dc, at the centers of single slits and of arrangements of mechanically interacting slits under uni-axial compressive far-field loads. Our main objective is to quantitatively study the role of the following geometrical parameters in stimulus transformation: aspect ratio, slit shape, geometry of the slits' centerlines, load direction, lateral distance S, longitudinal shift lambda, and difference in slit length Deltal between neighboring slits. Slit face displacements are primarily sensitive to slit length and load direction but little affected by aspect ratios between 20 and 100. In stacks of five parallel slits at lateral distances typical of lyriform organs (S=0.03 l) the longitudinal shift lambda substantially influences slit compression. A change of lambda from 0 to 0.85 l causes changes of up to 420% in Dc. Even minor morphological variations in the arrangements can substantially influence the stimulus transformation. The site of transduction in real slit sensilla does not always coincide with the position of maximum slit compression predicted by simplified models.
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Affiliation(s)
- Bernhard Hössl
- Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, Gusshausstrasse 27-29/317, 1040, Vienna, Austria
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