Recent progress in flexible tactile sensor systems: from design to application

Abstract

With the rapid development of artificial intelligence, human-machine interaction, and healthcare systems, flexible tactile sensors have huge market potentials and research needs, so that both fundamental research and application demonstrations are evolving rapidly to push the potential to reality. In this review, we briefly summarize the recent progress of the flexible tactile sensor system, including the common sensing mechanisms, the important performance evaluation parameters, the device design trend, and the main applications. Moreover, the current device design trend towards flexible tactile sensor systems is discussed, including novel structures for outstanding performance, sensor arrays for large-area information acquisition, multi-mode information acquisition, and integration of tactile sensors with transistors. Various emerging applications enabled with these sensors are also exemplified in this review to show the potentials of the tactile sensors. Finally, we also discuss the technical demands and the future perspectives of flexible tactile sensor systems.

Keywords

Tactile sensor / flexible sensing / sensor system

References

[1] Zhu M,Lee C.Technologies toward next generation human machine interfaces: From machine learning enhanced tactile sensing to neuromorphic sensory systems.Applied Physics Reviews2020;7:031305

[2] Dahiya RS,Valle M,Lumelsky VJ.Directions toward effective utilization of tactile skin: a review.IEEE Sensors J2013;13:4121-38

[3] Wang D,Shen G.Nanofiber/nanowires-based flexible and stretchable sensors.J Semicond2020;41:041605

[4] Takei K,Wang C.Physical and chemical sensing with electronic skin.Proc IEEE2019;107:2155-67

[5] Qi D,Tian G,Huang Y.Stretchable electronics based on PDMS substrates.Adv Mater2021;33:e2003155

[6] Ma Z,Pan L.Skin-inspired electronics: emerging semiconductor devices and systems.J Semicond2020;41:041601

[7] Li J,Tao J,Pan C.Recent progress in flexible pressure sensor arrays: from design to applications.J Mater Chem C2018;6:11878-92

[8] Li D,Gao Z,Yu X.Department of Biomedical EngineeringCity University of Hong KongHong KongChinaRecent progress of skin-integrated electronics for intelligent sensing.Light: Advanced Manufacturing2021;2:39-58

[9] Kumar S,Tripathi N.Review - recent advances in the development of carbon nanotubes based flexible sensors.J Electrochem Soc2020;167:047506

[10] Kim JJ,Wang H,Yokota T.Skin electronics: next-generation device platform for virtual and augmented reality.Adv Funct Mater2021;

[11] Jiang C,Nathan A.Flexible ultralow-power sensor interfaces for E-skin.Proc IEEE2019;107:2084-105

[12] Jeon S,Trung TQ,Lee N.Flexible multimodal sensors for electronic skin: principle, materials, device, array architecture, and data acquisition method.Proc IEEE2019;107:2065-83

[13] Heo JS,Kim I.Challenges in design and fabrication of flexible/stretchable carbon- and textile-based wearable sensors for health monitoring: a critical review.Sensors (Basel)2020;20:3927 PMCID:PMC7412463

[14] Cheng G,Bergner F,Leboutet Q.A comprehensive realization of robot skin: sensors, sensing, control, and applications.Proc IEEE2019;107:2034-51

[15] Chen W.Progress in achieving high-performance piezoresistive and capacitive flexible pressure sensors: A review.J Mater Sci Mater Med2020;43:175-88

[16] Bariya M,Javey A.Wearable sweat sensors.Nat Electron2018;1:160-71

[17] Miao P,Zhang C,Cheng S.Graphene nanostructure-based tactile sensors for electronic skin applications.Nanomicro Lett2019;11:71 PMCID:PMC7770800

[18] Wan Y,Guo CF.Recent progresses on flexible tactile sensors.Materials Today Physics2017;1:61-73

[19] Huang S,Zhao Y,Guo CF.Flexible electronics: stretchable electrodes and their future.Adv Funct Mater2019;29:1805924

[20] Lee S,Hassani FA.Nanomesh pressure sensor for monitoring finger manipulation without sensory interference.Science2020;370:966-70

[21] Wang B,Xie Z.Flexible and stretchable metal oxide nanofiber networks for multimodal and monolithically integrated wearable electronics.Nat Commun2020;11:2405 PMCID:PMC7229221

[22] Park Y,Kwak SS.Wireless, skin-interfaced sensors for compression therapy.Sci Adv2020;6:eabe1655 PMCID:PMC7821894

[23] Chung HU,Hourlier-Fargette A.Skin-interfaced biosensors for advanced wireless physiological monitoring in neonatal and pediatric intensive-care units.Nat Med2020;26:418-29 PMCID:PMC7315772

[24] Kwak JW,Xie Z.Wireless sensors for continuous, multimodal measurements at the skin interface with lower limb prostheses.Sci Transl Med2020;12:eabc4327 PMCID:PMC7775724

[25] Sun T,McIntosh RT.Decoding of facial strains via conformable piezoelectric interfaces.Nat Biomed Eng2020;4:954-72

[26] Tai LC,Nyein HYY.Nicotine monitoring with a wearable sweat band.ACS Sens2020;5:1831-7

[27] Lin Y,Javey A.Wearable Biosensors for Body Computing.Adv Funct Mater2020;

[28] Liu Q,Wu F.Highly sensitive and wearable In₂O₃ nanoribbon transistor biosensors with integrated on-chip gate for glucose monitoring in body fluids.ACS Nano2018;12:1170-8

[29] Xie C,Du W.Sensing-range-tunable pressure sensors realized by self-patterned-spacer design and vertical CNT arrays embedded in PDMS.RSC Adv2020;10:33558-65

[30] Park J,Hong J.Giant tunneling piezoresistance of composite elastomers with interlocked microdome arrays for ultrasensitive and multimodal electronic skins.ACS Nano2014;8:4689-97

[31] Bae GY,Kim D.Linearly and highly pressure-sensitive electronic skin based on a bioinspired hierarchical structural array.Adv Mater2016;28:5300-6

[32] Won SM,Kim BH.Multimodal sensing with a three-dimensional piezoresistive structure.ACS Nano2019;13:10972-9

[33] Zhu P,Wang Y,Zhang Q.Flexible 3D architectured piezo/thermoelectric bimodal tactile sensor array for E-skin application.Adv Energy Mater2020;10:2001945

[34] Sun X,Li T.Flexible tactile electronic skin sensor with 3D force detection based on porous CNTs/PDMS nanocomposites.Nanomicro Lett2019;11:57 PMCID:PMC7770749

[35] Zhao J,Zhou Z.Novel multi-walled carbon nanotubes-embedded laser-induced graphene in crosslinked architecture for highly responsive asymmetric pressure sensor.Sensors and Actuators A: Physical2021;323:112658

[36] Wang Z,Huang H,Lin W.Full 3D printing of stretchable piezoresistive sensor with hierarchical porosity and multimodulus architecture.Adv Funct Mater2019;29:1807569

[37] Zhao J,Yang R.Ultra-sensitive strain sensors based on piezoresistive nanographene films.Appl Phys Lett2012;101:063112

[38] Qiu L,Tang Y.Ultrafast dynamic piezoresistive response of graphene-based cellular elastomers.Adv Mater2016;28:194-200

[39] Park YJ,Shinde SM.All MoS₂-based large area, skin-attachable active-matrix tactile sensor.ACS Nano2019;13:3023-30

[40] Park J,Hong J.Tactile-direction-sensitive and stretchable electronic skins based on human-skin-inspired interlocked microstructures.ACS Nano2014;8:12020-9

[41] Pan L,Yu G.An ultra-sensitive resistive pressure sensor based on hollow-sphere microstructure induced elasticity in conducting polymer film.Nat Commun2014;5:3002

[42] Huang Y,Ma C.Sensitive pressure sensors based on conductive microstructured air-gap gates and two-dimensional semiconductor transistors.Nat Electron2020;3:59-69

[43] Liu Q,Li C.Highly transparent and flexible iontronic pressure sensors based on an opaque to transparent transition.Adv Sci (Weinh)2020;7:2000348 PMCID:PMC7237840

[44] Bai N,Wang Q.Graded intrafillable architecture-based iontronic pressure sensor with ultra-broad-range high sensitivity.Nat Commun2020;11:209 PMCID:PMC6954251

[45] Yang X,Shi Y,Zhou B.A flexible highly sensitive capacitive pressure sensor.Sensors and Actuators A: Physical2021;324:112629

[46] Fu M,Jin Y,Huang S.A highly sensitive, reliable, and high-temperature-resistant flexible pressure sensor based on ceramic nanofibers.Adv Sci (Weinh)2020;7:2000258 PMCID:PMC7507114

[47] Qiu Z,Zhou W.Ionic skin with biomimetic dielectric layer templated from calathea zebrine leaf.Adv Funct Mater2018;28:1802343

[48] Sarwar MS,Preston C,Mirabbasi S.Bend, stretch, and touch: locating a finger on an actively deformed transparent sensor array.Sci Adv2017;3:e1602200 PMCID:PMC5351976

[49] Tee BC,Dunn RR,Eason E.Tunable flexible pressure sensors using microstructured elastomer geometries for intuitive electronics.Adv Funct Mater2014;24:5427-34

[50] Navaraj W.Fingerprint-enhanced capacitive-piezoelectric flexible sensing skin to discriminate static and dynamic tactile stimuli.Advanced Intelligent Systems2019;1:1900051

[51] Mu C,Huang W.Flexible normal-tangential force sensor with opposite resistance responding for highly sensitive artificial skin.Adv Funct Mater2018;28:1707503

[52] Dagdeviren C,Joe P.Conformable amplified lead zirconate titanate sensors with enhanced piezoelectric response for cutaneous pressure monitoring.Nat Commun2014;5:4496

[53] Park DY,Kim DH.Self-powered real-time arterial pulse monitoring using ultrathin epidermal piezoelectric sensors.Adv Mater2017;29:1702308

[54] Dagdeviren C,Su Y.Conformal piezoelectric energy harvesting and storage from motions of the heart, lung, and diaphragm.Proc Natl Acad Sci U S A2014;111:1927-32 PMCID:PMC3918766

[55] Dagdeviren C,Joe P.Flexible piezoelectric devices for gastrointestinal motility sensing.Nat Biomed Eng2017;1:807-17

[56] Nguyen TD,Nagarah JM.Piezoelectric nanoribbons for monitoring cellular deformations.Nat Nanotechnol2012;7:587-93

[57] Deng W,Jin L.Cowpea-structured PVDF/ZnO nanofibers based flexible self-powered piezoelectric bending motion sensor towards remote control of gestures.Nano Energy2019;55:516-25

[58] Yang Y,Xie G.Flexible piezoelectric pressure sensor based on polydopamine-modified BaTiO3/PVDF composite film for human motion monitoring.Sensors and Actuators A: Physical2020;301:111789

[59] Djohan N,Liman J,Husein I.The effect of indium oxide (In₂O₃) dopant on the electrical properties of LiTaO₃ thin film-based sensor.Ferroelectrics2020;568:55-61

[60] Wang M,Ma T.High-frequency vibration analysis of LiTaO₃ piezoelectric plates excited by lateral electric fields produced by surface electrodes under viscous liquid loadings for sensing.Smart Mater Struct2020;29:045004

[61] Chen J,Wang W.High durable, biocompatible, and flexible piezoelectric pulse sensor using single-crystalline III-N thin film.Adv Funct Mater2019;29:1903162

[62] Kim N,Chen J.Piezoelectric pressure sensor based on flexible gallium nitride thin film for harsh-environment and high-temperature applications.Sensors and Actuators A: Physical2020;305:111940

[63] Cheng S,Cao Z,Fang X.Wearable and ultrasensitive strain sensor based on high-quality GaN pn junction microwire arrays.Small2020;16:e1907461

[64] Kar E,Dutta B,Mukherjee S.Ultraviolet- and microwave-protecting, self-cleaning e-skin for efficient energy harvesting and tactile mechanosensing.ACS Appl Mater Interfaces2019;11:17501-12

[65] Su Y,Pan H.Muscle fibers inspired high-performance piezoelectric textiles for wearable physiological monitoring.Adv Funct Mater2021;31:2010962

[66] Lu K,Guo J.Ultra-sensitive strain sensor based on flexible poly(vinylidene fluoride) piezoelectric film.Nanoscale Res Lett2018;13:83 PMCID:PMC5852243

[67] Wang ZL.On the origin of contact-electrification.Materials Today2019;30:34-51

[68] Fan F,Lin Wang Z.Flexible triboelectric generator.Nano Energy2012;1:328-34

[69] Tian J,Wang ZL.Environmental energy harvesting based on triboelectric nanogenerators.Nanotechnology2020;31:242001

[70] Wang X,Zhang X.A highly stretchable transparent self-Powered triboelectric tactile sensor with metallized nanofibers for wearable electronics.Adv Mater2018;30:e1706738

[71] Wang X,Dong L.Self-powered high-resolution and pressure-sensitive triboelectric sensor matrix for real-time tactile mapping.Adv Mater2016;28:2896-903

[72] Sun H,Wang C.Ultra-stretchable, durable and conductive hydrogel with hybrid double network as high performance strain sensor and stretchable triboelectric nanogenerator.Nano Energy2020;76:105035

[73] Chun S,Kim H,Pang C.Self-powered pressure- and vibration-sensitive tactile sensors for learning technique-based neural finger skin.Nano Lett2019;19:3305-12

[74] Mannsfeld SC,Stoltenberg RM.Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers.Nat Mater2010;9:859-64

[75] Zhang S,Wang H,Zhang M.Vertical CNT-Ecoflex nanofins for highly linear broad-range-detection wearable strain sensors.J Mater Chem C2018;6:5132-9

[76] Lou Z,Wang L,Shen G.An ultra-sensitive and rapid response speed graphene pressure sensors for electronic skin and health monitoring.Nano Energy2016;23:7-14

[77] Pan F,Li Y.3D graphene films enable simultaneously high sensitivity and large stretchability for strain sensors.Adv Funct Mater2018;28:1803221

[78] Boutry CM,Schroeder BC.A stretchable and biodegradable strain and pressure sensor for orthopaedic application.Nat Electron2018;1:314-21

[79] Chen S,Ding D,Xu F.Flexible and anisotropic strain sensor based on carbonized crepe paper with aligned cellulose fibers.Adv Funct Mater2018;28:1802547

[80] Shi C,Lei Z,Zhang W.Heterogeneous integration of rigid, soft, and liquid materials for self-healable, recyclable, and reconfigurable wearable electronics.Sci Adv2020;6:eabd0202 PMCID:PMC7673720

[81] Yu X,Yu Y.Skin-integrated wireless haptic interfaces for virtual and augmented reality.Nature2019;575:473-9

[82] Xu F,Shi Y.Recent developments for flexible pressure sensors: a review.Micromachines (Basel)2018;9:580 PMCID:PMC6266671

[83] Wang C,Wang H,Yin Z.Advanced carbon for flexible and wearable electronics.Adv Mater2019;31:e1801072

[84] Kang M,Jang B,Kim JH.Graphene-based three-dimensional capacitive touch sensor for wearable electronics.ACS Nano2017;11:7950-7

[85] Zeng X,Zhang H.Tunable, ultrasensitive, and flexible pressure sensors based on wrinkled microstructures for electronic skins.ACS Appl Mater Interfaces2019;11:21218-26

[86] Gong S,Wang Y.A wearable and highly sensitive pressure sensor with ultrathin gold nanowires.Nat Commun2014;5:3132

[87] Liu Y,Zhao L.Electronic skin from high-throughput fabrication of intrinsically stretchable lead zirconate titanate elastomer.Research (Wash D C)2020;2020:1085417 PMCID:PMC7586250

[88] Qiu Y,Sun S.Bioinspired, multifunctional dual-mode pressure sensors as electronic skin for decoding complex loading processes and human motions.Nano Energy2020;78:105337

[89] Hwang B,Trung TQ.A transparent stretchable sensor for distinguishable detection of touch and pressure by capacitive and piezoresistive signal transduction.NPG Asia Mater2019;11

[90] Yang Y,Cheng X,Fu Q.Stretchable and healable conductive elastomer based on PEDOT:PSS/natural rubber for self-powered temperature and strain sensing.ACS Appl Mater Interfaces2021;13:14599-611

[91] You I,Matsuhisa N.Artificial multimodal receptors based on ion relaxation dynamics.Science2020;370:961-5

[92] Wang J,Zhang C.Energy-efficient, fully flexible, high-performance tactile sensor based on piezotronic effect: Piezoelectric signal amplified with organic field-effect transistors.Nano Energy2020;76:105050

[93] Oh H,Yip M.Scalable tactile sensor arrays on flexible substrates with high spatiotemporal resolution enabling slip and grip for closed-loop robotics.Sci Adv2020;6:eabd7795 PMCID:PMC7673764

[94] Guo S,Li C.Integrated contact lens sensor system based on multifunctional ultrathin MoS₂ transistors.Matter2021;4:969-85 PMCID:PMC7773002

[95] Shi Q,Lee C.More than energy harvesting - combining triboelectric nanogenerator and flexible electronics technology for enabling novel micro-/nano-systems.Nano Energy2019;57:851-71

[96] Zhao J,Zhang X.Intrinsically stretchable organic-tribotronic-transistor for tactile sensing.Research (Wash D C)2020;2020:1398903 PMCID:PMC7333181

[97] Yang GZ,Dupont PE.The grand challenges of Science Robotics.Sci Robot2018;3:eaar7650

[98] Kim J,Heimgartner R.Reducing the metabolic rate of walking and running with a versatile, portable exosuit.Science2019;365:668-72

[99] Zhang J,Witte KA.Human-in-the-loop optimization of exoskeleton assistance during walking.Science2017;356:1280-4

[100] Valle G,Fogle E,Petrini FM.Mechanisms of neuro-robotic prosthesis operation in leg amputees.Sci Adv2021;7:eabd8354 PMCID:PMC8059925

[101] Li J,Gao W,Wang J.Micro/nanorobots for biomedicine: delivery, surgery, sensing, and detoxification.Sci Robot2017;2:eaam6431 PMCID:PMC6759331

[102] Miskin MZ,Dorsey K.Electronically integrated, mass-manufactured, microscopic robots.Nature2020;584:557-61

[103] Mishra S,Intarasirisawat J.Soft, wireless periocular wearable electronics for real-time detection of eye vergence in a virtual reality toward mobile eye therapies.Sci Adv2020;6:eaay1729 PMCID:PMC7069716

[104] Song K,Jin S.Pneumatic actuator and flexible piezoelectric sensor for soft virtual reality glove system.Sci Rep2019;9:8988 PMCID:PMC6639318

[105] Trung TQ.Flexible and stretchable physical sensor integrated platforms for wearable human-activity monitoringand personal healthcare.Adv Mater2016;28:4338-72

[106] Amjadi M,Park I.Stretchable, skin-mountable, and wearable strain sensors and their potential applications: a review.Adv Funct Mater2016;26:1678-98

[107] Ha M,Ko H.Wearable and flexible sensors for user-interactive health-monitoring devices.J Mater Chem B2018;6:4043-64

[108] Zheng YL,Poon CC.Unobtrusive sensing and wearable devices for health informatics.IEEE Trans Biomed Eng2014;61:1538-54 PMCID:PMC7176476

[109] Shin J,Bai W.Bioresorbable pressure sensors protected with thermally grown silicon dioxide for the monitoring of chronic diseases and healing processes.Nat Biomed Eng2019;3:37-46

[110] Wang Y,Deng Y.Self-powered wearable pressure sensing system for continuous healthcare monitoring enabled by flexible thin-film thermoelectric generator.Nano Energy2020;73:104773

[111] Wang C,Hu H.Monitoring of the central blood pressure waveform via a conformal ultrasonic device.Nat Biomed Eng2018;2:687-95 PMCID:PMC6428206

[112] Liu Q,Zhang J.Thermal, waterproof, breathable, and antibacterial cloth with a nanoporous structure.ACS Appl Mater Interfaces2018;10:2026-32

[113] Zhang L,Jiang W.Infrared skin-like active stretchable electronics based on organic-inorganic composite structures for promotion of cutaneous wound healing.Adv Mater Technol2019;4:1900150

[114] Ni X,Jeong H.Automated, multiparametric monitoring of respiratory biomarkers and vital signs in clinical and home settings for COVID-19 patients.Proc Natl Acad Sci U S A2021;118:e2026610118 PMCID:PMC8126790

[115] Araromi OA,Dorsey KL.Ultra-sensitive and resilient compliant strain gauges for soft machines.Nature2020;587:219-24