[1] [1] Xiong J, Chen J, Lee PS. Functional fibers and fabrics for soft robotics, wearables, and human-robot interface. Adv Mater. 2021;33:2002640.10.1002/adma.202002640

[2] [2] Zhao Y, Gao W, Dai K, Wang S, Yuan Z, Li J, Zhai W, Zheng G, Pan C, Liu C, Shen C. Bioinspired multifunctional photonic-electronic smart skin for ultrasensitive health monitoring, for visual and self-powered sensing. Adv Mater. 2021;33:2102332.10.1002/adma.202102332

[3] [3] Rich SI, Wood RJ, Majidi C. Untethered soft robotics. Nat Electron. 2018;1:102.10.1038/s41928-018-0024-1

[4] [4] Peng B, Zhao F, Ping J, Ying Y. Recent advances in nanomaterial-enabled wearable sensors: material synthesis, sensor design, and personal health monitoring. Small. 2020;16:2002681.10.1002/smll.202002681

[5] [5] Hong SY, Lee YH, Park H, Jin SW, Jeong YR, Yun J, You I, Zi G, Ha JS. Stretchable active matrix temperature sensor array of polyaniline nanofibers for electronic skin. Adv Mater. 2016;28:930.10.1002/adma.201504659

[6] [6] Yao C, Yin X, Yu Y, Cai Z, Wang X. Chemically functionalized natural cellulose materials for effective triboelectric nanogenerator development. Adv Funct Mater. 2017;27:1700794.10.1002/adfm.201700794

[7] [7] Iqbal SMA, Mahgoub I, Du E, Leavitt MA, Asghar W. Advances in healthcare wearable devices. Npj Flex Electron. 2021;5:9.10.1038/s41528-021-00107-x

[8] [8] Zhang Z, Wang L, Yu H, Zhang F, Tang L, Feng Y, Feng W. Highly transparent, self-healable, and adhesive organogels for bio-inspired intelligent ionic skins. ACS Appl Mater Inter. 2020;12:15657.10.1021/acsami.9b22707

[9] [9] Karan SK, Bera R, Paria S, Das AK, Maiti S, Maitra A, Khatua BB. An approach to design highly durable piezoelectric nanogenerator based on self-poled PVDF/AlO-rGO flexible nanocomposite with high power density and energy conversion efficiency. Adv Energy Mater. 2016;6:1601016.10.1002/aenm.201601016

[10] [10] Li J, Bao R, Tao J, Peng Y, Pan C. Recent progress in flexible pressure sensor arrays: from design to applications. J Mater Chem C. 2018;6:11878.10.1039/C8TC02946F

[11] [11] Zhang Y, Zhou L, Gao X, Liu C, Chen H, Zheng H, Gui J, Sun C, Yu L, Guo S. Performance-enhanced flexible piezoelectric nanogenerator via layer-by-layer assembly for self-powered vagal neuromodulation. Nano Energy. 2021;89: 106319.10.1016/j.nanoen.2021.106319

[12] [12] Zhang Z, Yu Y, Yu H, Feng Y, Feng W. Water-resistant conductive organogels with sensation and actuation functions for artificial neuro-sensory muscular systems. SmartMat. 2022;3:632.10.1002/smm2.1108

[13] [13] Yu Y, Feng Y, Liu F, Wang H, Yu H, Dai K, Zheng G, Feng W. Carbon dots-based ultrastretchable and conductive hydrogels for high-performance tactile sensors and self-powered electronic skin. Small. 2023;19:2204365.10.1002/smll.202204365

[14] [14] Gao L, Han Y, Surjadi JU, Cao K, Zhou W, Xu H, Hu X, Wang M, Fan K, Wang Y, Wang W, Espinosa HD. Magnetically induced micropillar arrays for an ultrasensitive flexible sensor with a wireless recharging system. Sci China Mater. 1977;2021:64.

[15] [15] Wang Y, Yokota T, Someya T. Electrospun nanofiber-based soft electronics. Npg Asia Mater. 2021;13:22.10.1038/s41427-020-00267-8

[16] [16] Sharma S, Chhetry A, Maharjan P, Zhang S, Shrestha K, Sharifuzzaman M, Bhatta T, Shin Y, Kim D, Lee S, Park JY. Polyaniline-nanospines engineered nanofibrous membrane based piezoresistive sensor for high-performance electronic skins. Nano Energy. 2022;95: 106970.10.1016/j.nanoen.2022.106970

[17] [17] Wang S, Tong W, Li Y, Zhang P, Liu Y, Chen Y, Zhang Y. Contributions of piezoelectricity and triboelectricity to a hydroxyapatite/PVDF–HFP fiber-film nanogenerator. Nano Energy. 2023;105: 108026.10.1016/j.nanoen.2022.108026

[18] [18] Chinnappan A, Baskar C, Baskar S, Ratheesh G, Ramakrishna S. An overview of electrospun nanofibers and their application in energy storage, sensors and wearable/flexible electronics. J Mater Chem C. 2017;5:12657.10.1039/C7TC03058D

[19] [19] Jin T, Pan Y, Jeon GJ, Yeom HI, Zhang S, Paik KW, Park SK. Ultrathin nanofibrous membranes containing insulating microbeads for highly sensitive flexible pressure sensors. ACS Appl Mater Inter. 2020;12:13348.10.1021/acsami.0c00448

[20] [20] Li Y, Xu M, Xia Y, Wu J, Sun X, Wang S, Hu G, Xiong C. Multilayer assembly of electrospun/electrosprayed PVDF-based nanofibers and beads with enhanced piezoelectricity and high sensitivity. Chem Eng J. 2020;388: 124205.10.1016/j.cej.2020.124205

[21] [21] Li J, Yin J, Wee MGV, Chinnappan A, Ramakrishna S. A self-powered piezoelectric nanofibrous membrane as wearable tactile sensor for human body motion monitoring and recognition. Adv Fiber Mater. 2023;5:1417.10.1007/s42765-023-00282-8

[22] [22] Zhang J, Yang T, Tian G, Lan B, Deng W, Tang L, Ao Y, Sun Y, Zeng W, Ren X, Li Z, Jin L, Yang W. Spatially confined MXene/PVDF nanofiber piezoelectric electronics. Adv Fiber Mater. 2023. .10.1007/s42765-023-00337-w

[23] [23] Dong K, Peng X, Wang ZL. Fiber/fabric-based piezoelectric and triboelectric nanogenerators for flexible/stretchable and wearable electronics and artificial intelligence. Adv Mater. 2020;32:1902549.10.1002/adma.201902549

[24] [24] Su Y, Chen C, Pan H, Yang Y, Chen G, Zhao X, Li W, Gong Q, Xie G, Zhou Y, Zhang S, Tai H, Jiang Y, Chen J. Muscle fibers inspired high-performance piezoelectric textiles for wearable physiological monitoring. Adv Funct Mater. 2021;31:2010962.10.1002/adfm.202010962

[25] [25] Sultana A, Ghosh SK, Alam MM, Sadhukhan P, Roy K, Xie M, Bowen CR, Sarkar S, Das S, Middya TR, Mandal D. Methylammonium lead iodide incorporated poly(vinylidene fluoride) nanofibers for flexible piezoelectric-pyroelectric nanogenerator. ACS Appl Mater Inter. 2019;11:27279.10.1021/acsami.9b04812

[26] [26] Kim SR, Yoo JH, Kim JH, Cho YS, Park JW. Mechanical and piezoelectric properties of surface modified (Na, K)NbO3-based nanoparticle-embedded piezoelectric polymer composite nanofibers for flexible piezoelectric nanogenerators. Nano Energy. 2021;79: 105445.10.1016/j.nanoen.2020.105445

[27] [27] Wan X, Wang Z, Zhao X, Hu Q, Li Z, Lin Wang Z, Li L. Flexible and highly piezoelectric nanofibers with organic–inorganic coaxial structure for self-powered physiological multimodal sensing. Chem Eng J. 2023;451: 139077.10.1016/j.cej.2022.139077

[28] [28] Wu S, Zabihi F, Yeap RY, Darestani MRY, Bahi A, Wan Z, Yang S, Servati P, Ko FK. Cesium lead halide perovskite decorated polyvinylidene fluoride nanofibers for wearable piezoelectric nanogenerator yarns. ACS Nano. 2023;17:1022.10.1021/acsnano.2c07320

[29] [29] Vijayakanth T, Liptrot DJ, Gazit E, Boomishankar R, Bowen CR. Recent advances in organic and organic-inorganic hybrid materials for piezoelectric mechanical energy harvesting. Adv Funct Mater. 2022;32:2109492.10.1002/adfm.202109492

[30] [30] Chen S, Zhu P, Mao L, Wu W, Lin H, Xu D, Lu X, Shi J. Piezocatalytic medicine: an emerging frontier using piezoelectric materials for biomedical applications. Adv Mater. 2023;35:2208256.10.1002/adma.202208256

[31] [31] Zhang S, Liu H, Tang N, Ge J, Yu J, Ding B. Direct electronetting of high-performance membranes based on self-assembled 2D nanoarchitectured networks. Nat Commun. 2019;10:1458.10.1038/s41467-019-09444-y

[32] [32] Gong X, Ding M, Gao P, Liu X, Yu J, Zhang S, Ding B. High-performance liquid-repellent and thermal-wet comfortable membranes using triboelectric nanostructured nanofiber/meshes. Adv Mater. 2023;35:2305606.10.1002/adma.202305606

[33] [33] Li T, Qu M, Carlos C, Gu L, Jin F, Yuan T, Wu X, Xiao J, Wang T, Dong W, Wang X, Feng ZQ. High-performance poly(vinylidene difluoride)/dopamine core/shell piezoelectric nanofiber and its application for biomedical sensors. Adv Mater. 2021;33:2006093.10.1002/adma.202006093

[34] [34] Luo J, Fang CC, Wu NL. High polarity poly(vinylidene difluoride) thin coating for dendrite-free and high-performance lithium metal anodes. Adv Energy Mater. 2017;8:1701482.10.1002/aenm.201701482

[35] [35] Jaleh B, Jabbari A. Evaluation of reduced graphene oxide/ZnO effect on properties of PVDF nanocomposite films. Appl Surf Sci. 2014;320:339.10.1016/j.apsusc.2014.09.030

[36] [36] Wang C, Zhang J, Gong S, Ren K. Significantly enhanced breakdown field for core-shell structured poly(vinylidene fluoride-hexafluoropropylene)/TiO2 nanocomposites for ultra-high energy density capacitor applications. J Appl Phys. 2018;124: 154103.10.1063/1.5049405

[37] [37] Zhang J, Du X, Wang C, Ren K. Poly(vinylidene fluoride-hexafluoropropylene) based blend film for ultrahigh energy density capacitor applications. J Phys D Appl Phys. 2018;51: 255306.10.1088/1361-6463/aac55f

[38] [38] Soin N, Shah TH, Anand SC, Geng J, Pornwannachai W, Mandal P, Reid D, Sharma S, Hadimani RL, Bayramol DV, Siores E. Novel “3-D spacer” all fibre piezoelectric textiles for energy harvesting applications. Energy Environ Sci. 2014;7:1670.10.1039/C3EE43987A

[39] [39] Maji S, Sarkar PK, Aggarwal L, Ghosh SK, Mandal D, Sheet G, Acharya S. Self-oriented beta-crystalline phase in the polyvinylidene fluoride ferroelectric and piezo-sensitive ultrathin Langmuir–Schaefer film. Phys Chem Chem Phys. 2015;17:8159.10.1039/C5CP00218D

[40] [40] Wang X, Ding B, Sun G, Wang M, Yu J. Electro-spinning/netting: a strategy for the fabrication of three-dimensional polymer nano-fiber/nets. Prog Mater Sci. 2013;58:1173.10.1016/j.pmatsci.2013.05.001

[41] [41] Zhang S, Chen K, Yu J, Ding B. Model derivation and validation for 2D polymeric nanonets: origin, evolution, and regulation. Polymer. 2015;74:182.10.1016/j.polymer.2015.08.002

[42] [42] Sahay R, Teo CJ, Chew YT. New correlation formulae for the straight section of the electrospun jet from a polymer drop. J Fluid Mech. 2013;735:150.10.1017/jfm.2013.497

[43] [43] Wilm M. Principles of electrospray ionization. Mol Cell Proteomics. 2011;10(M111): 009407.

[44] [44] Han Y, Koplik J, Maldarelli C. Surfactant and dilatational viscosity effects on the deformation of liquid droplets in an electric field. J Colloid Interface Sci. 2022;607:900.10.1016/j.jcis.2021.07.105

[45] [45] Soin N, Boyer D, Prashanthi K, Sharma S, Narasimulu AA, Luo J, Shah TH, Siores E, Thundat T. Exclusive self-aligned beta-phase PVDF films with abnormal piezoelectric coefficient prepared via phase inversion. Chem Commun (Camb). 2015;51:8257.10.1039/C5CC01688F

[46] [46] Li H, Lim S. High-performance piezoelectric nanogenerators featuring embedded organic nanodroplets for self-powered sensors. J Mater Chem A. 2022;10:14894.10.1039/D2TA02276A

[47] [47] Liu Z, Li S, Zhu J, Mi L, Zheng G. Fabrication of beta-phase-enriched PVDF sheets for self-powered piezoelectric sensing. ACS Appl Mater Inter. 2022;14:11854.10.1021/acsami.2c01611

[48] [48] Yuan M, Ma R, Ye Q, Bai X, Li H, Yan F, Liu C, Ren Y, Wang Z. Melt-stretched poly(vinylidene fluoride)/zinc oxide nanocomposite films with enhanced piezoelectricity by stress concentrations in piezoelectric domains for wearable electronics. Chem Eng J. 2023;455: 140771.10.1016/j.cej.2022.140771

[49] [49] Sessler GM, Hillenbrand J. Electromechanical response of cellular electret films. Appl Phys Lett. 1999;75:3405.10.1063/1.125308

[50] [50] Li W, Wu N, Zhong J, Zhong Q, Zhao S, Wang B, Cheng X, Li S, Liu K, Hu B, Zhou J. Theoretical study of cellular piezoelectret generators. Adv Funct Mater. 1964;2016:26.

[51] [51] Mo X, Zhou H, Li W, Xu Z, Duan J, Huang L, Hu B, Zhou J. Piezoelectrets for wearable energy harvesters and sensors. Nano Energy. 2019;65: 104033.10.1016/j.nanoen.2019.104033

[52] [52] He L, Lu J, Han C, Liu X, Liu J, Zhang C. Electrohydrodynamic pulling consolidated high-efficiency 3D printing to architect unusual self-polarized beta-PVDF arrays for advanced piezoelectric sensing. Small. 2022;18:2200114.10.1002/smll.202200114

[53] [53] Lee JH, Yoon HJ, Kim TY, Gupta MK, Lee JH, Seung W, Ryu H, Kim SW. Micropatterned P(VDF-TrFE) film-based piezoelectric nanogenerators for highly sensitive self-powered pressure sensors. Adv Funct Mater. 2015;25:3203.10.1002/adfm.201500856

[54] [54] Xu F, Yang J, Dong R, Jiang H, Wang C, Liu W, Jiang Z, Zhang X, Zhu G. Wave-shaped piezoelectric nanofiber membrane nanogenerator for acoustic detection and recognition. Adv Fiber Mater. 2021;3:368.10.1007/s42765-021-00095-7

[55] [55] Ghosh SK, Park J, Na S, Kim MP, Ko H. A fully biodegradable ferroelectric skin sensor from edible porcine skin gelatine. Adv Sci. 2021;8:2005010.10.1002/advs.202005010

[56] [56] Nichols WW. Clinical measurement of arterial stiffness obtained from noninvasive pressure waveforms. Am J Hypertens. 2005;18:3S.10.1016/j.amjhyper.2004.10.009

[57] [57] Huang CM, Chang HC, Kao ST, Li TC, Wei CC, Chen C, Liao YT, Chen FJ. Radial pressure pulse and heart rate variability in heat- and cold-stressed humans. Evid-based Compl Alt. 2011;2011: 751317.10.1155/2011/751317

[58] [58] Cao X, Xiong Y, Sun J, Zhu X, Sun Q, Wang ZL. Piezoelectric nanogenerators derived self-powered sensors for multifunctional applications and artificial intelligence.pdf. Adv Funct Mater. 2021;31:2102983.10.1002/adfm.202102983

[59] [59] Faraz M, Singh HH, Khare N. A progressive strategy for harvesting mechanical energy using flexible PVDF-rGO-MoS2 nanocomposites film-based piezoelectric nanogenerator. J Alloys Compd. 2022;890: 161840.10.1016/j.jallcom.2021.161840

[60] [60] Garain S, Jana S, Sinha TK, Mandal D. Design of in situ poled Ce(3+)-doped electrospun PVDF/graphene composite nanofibers for fabrication of nanopressure sensor and ultrasensitive acoustic nanogenerator. ACS Appl Mater Inter. 2016;8:4532.10.1021/acsami.5b11356

[61] [61] Yi J, Song Y, Cao Z, Li C, Xiong C. Gram-scale Y-doped ZnO and PVDF electrospun film for piezoelectric nanogenerators. Compos Sci Technol. 2021;215: 109011.10.1016/j.compscitech.2021.109011

[62] [62] Panda S, Hajra S, Jeong H, Panigrahi BK, Pakawanit P, Dubal D, Hong S, Kim HJ. Biocompatible CaTiO3-PVDF composite-based piezoelectric nanogenerator for exercise evaluation and energy harvesting. Nano Energy. 2022;102: 107682.10.1016/j.nanoen.2022.107682

[63] [63] Yan M, Liu S, Xu Q, Xiao Z, Yuan X, Zhou K, Zhang D, Wang Q, Bowen C, Zhong J, Zhang Y. Enhanced energy harvesting performance in lead-free multi-layer piezoelectric composites with a highly aligned pore structure. Nano Energy. 2023;106: 108096.10.1016/j.nanoen.2022.108096