Abstract
Background: The development of high-performance piezoelectric pressure sensors with outstanding sensitivity, good linearity, flexibility, durability, and biocompatibility is of great significance for smart robotics, human healthcare devices, smart sensors, and electronic skin. Thus, considerable progress has been achieved in enhancing the piezoelectric property of PVDF-TrFEbased composite pressure sensors by adding various ZnO nanostructures in PVDF-TrFE polymer acting as a nucleating agent and dielectric material.
Aims: In this work, flexible pressure sensors with a sandwich structure based on PVDFTrFE/ nano-ZnO composite sensing film were fabricated using a simple spin-coating method and post-annealing process, while electrospinning and high-voltage polarization processes were not adopted.
Methods: Poly (vinylidene fluoride-trifluoroethylene) (PVDF-TrFE)/nano-ZnO composite films were prepared via spin coating to fabricate flexible piezoelectric pressure sensors. ZnO nanoparticles (ZnO NPs), tetrapod ZnO (T-ZnO) and ZnO nanorods (ZnO NRs) were used as nano-fillers for piezoelectric PVDF-TrFE, to enhance the beta-crystal ratio as well as the crystallinity of PVDF-TrFE. The structural and surface morphologies of the composite films were investigated using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Results: Among three different types of ZnO nanostructures with a concentration range (0-7.5 wt%), the sensor with 0.75 wt% ZnO NRs nanofiller exhibits a maximum output voltage of 1.73 V under an external pressure of 3 N and a maximum sensitivity of 586.3 mV/N at the range of 0-3 N. Further, the sensor can generate a clear piezoelectric voltage under bending and twisting deformation as well as compression and tensile deformation.
Conclusion: To summarize, the addition of different concentrations of nano-ZnO can remarkably improve the piezoelectric performance of the composite sensor, and ZnO NRs can achieve better piezoelectric properties of the sensor as compared to ZnO NPs and T-ZnO. In addition, the sensor with 0.75 wt% ZnO NRs as nanofiller has the highest piezoelectric response, which is about 2.4 times that of the pure PVDF-TrFE sensor. It is demonstrated that the sensor has great potential applications in wearable health monitoring systems and mechanical stress measurement electronics.
Graphical Abstract
[1]
Iqbal, S.M.A.; Mahgoub, I.; Du, E.; Leavitt, M.A.; Asghar, W. Advances in healthcare wearable devices. npj Flex Electron, 2021, 5, 9.
[2]
Hou, Z.; Li, Z.; Fadiji, T.; Fu, J. Soft grasping mechanism of human fingers for tomato-picking bionic robots. Comput. Electron. Agric., 2021, 182, 106010.
[http://dx.doi.org/10.1016/j.compag.2021.106010]
[http://dx.doi.org/10.1016/j.compag.2021.106010]
[3]
Ye, L.; Chen, L.; Yu, J.; Tu, S.; Yan, B.; Zhao, Y.; Bai, X.; Gu, Y.; Chen, S. High-performance piezoelectric nanogenerator based on electrospun ZnO nanorods/P(VDF-TrFE) composite membranes for energy harvesting application. J. Mater. Sci. Mater. Electron., 2021, 32(4), 3966-3978.
[http://dx.doi.org/10.1007/s10854-020-05138-0]
[http://dx.doi.org/10.1007/s10854-020-05138-0]
[4]
Caponetto, R.; Di Pasquale, G.; Famoso, C.; Graziani, S.; Pollicino, A. A generating all-polymeric touching sensing system. IEEE Trans. Instrum. Meas., 2020, 69(7), 4545-4554.
[http://dx.doi.org/10.1109/TIM.2019.2947122]
[http://dx.doi.org/10.1109/TIM.2019.2947122]
[5]
Ha, K.H.; Zhang, W.; Jang, H.; Kang, S.; Wang, L.; Tan, P.; Hwang, H.; Lu, N. Highly sensitive capacitive pressure sensors over a wide pressure range enabled by the hybrid responses of a highly porous nanocomposite. Adv. Mater., 2021, 33(48), 2103320.
[http://dx.doi.org/10.1002/adma.202103320] [PMID: 34569100]
[http://dx.doi.org/10.1002/adma.202103320] [PMID: 34569100]
[6]
Gao, L.; Cao, K.; Hu, X.; Xiao, R.; Gan, B.; Wang, W.; Lu, Y. Nano electromechanical approach for flexible piezoresistive sensor. Appl. Mater. Today, 2020, 18, 100475.
[http://dx.doi.org/10.1016/j.apmt.2019.100475]
[http://dx.doi.org/10.1016/j.apmt.2019.100475]
[7]
Lei, H.; Chen, Y.; Gao, Z.; Wen, Z.; Sun, X. Advances in self-powered triboelectric pressure sensors. J. Mater. Chem. A Mater. Energy Sustain., 2021, 9(36), 20100-20130.
[http://dx.doi.org/10.1039/D1TA03505C]
[http://dx.doi.org/10.1039/D1TA03505C]
[8]
Fiorillo, A.S. Design and characterization of a PVDF ultrasonic range sensor. IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 1992, 39(6), 688-692.
[http://dx.doi.org/10.1109/58.165552] [PMID: 18267683]
[http://dx.doi.org/10.1109/58.165552] [PMID: 18267683]
[9]
Yuan, X.; Gao, X.; Shen, X.; Yang, J.; Li, Z.; Dong, S. A 3D-printed, alternatively tilt-polarized PVDF-TrFE polymer with enhanced piezoelectric effect for self-powered sensor application. Nano Energy, 2021, 85, 105985.
[http://dx.doi.org/10.1016/j.nanoen.2021.105985]
[http://dx.doi.org/10.1016/j.nanoen.2021.105985]
[10]
Kim, M.; Wu, Y.; Kan, E.; Fan, J. Breathable and flexible piezoelectric ZnO@PVDF fibrous nanogenerator for wearable applications. Polymers, 2018, 10(7), 745.
[http://dx.doi.org/10.3390/polym10070745] [PMID: 30960670]
[http://dx.doi.org/10.3390/polym10070745] [PMID: 30960670]
[11]
Lu, L.; Ding, W.; Liu, J.; Yang, B. Flexible PVDF based piezoelectric nanogenerators. Nano Energy, 2020, 78, 105251.
[http://dx.doi.org/10.1016/j.nanoen.2020.105251]
[http://dx.doi.org/10.1016/j.nanoen.2020.105251]
[12]
Chen, X.; Han, X.; Shen, Q.D. PVDF-based ferroelectric polymers in modern flexible electronics. Adv. Electron. Mater., 2017, 3(5), 1600460.
[http://dx.doi.org/10.1002/aelm.201600460]
[http://dx.doi.org/10.1002/aelm.201600460]
[13]
Wang, X.; Sun, F.; Yin, G.; Wang, Y.; Liu, B.; Dong, M. Tactile-sensing based on flexible pvdf nanofibers via electrospinning: a review. Sensors, 2018, 18(2), 330.
[http://dx.doi.org/10.3390/s18020330] [PMID: 29364175]
[http://dx.doi.org/10.3390/s18020330] [PMID: 29364175]
[14]
Kang, G.; Cao, Y. Application and modification of poly(vinylidene fluoride) (PVDF) membranes – A review. J. Membr. Sci., 2014, 463, 145-165.
[http://dx.doi.org/10.1016/j.memsci.2014.03.055]
[http://dx.doi.org/10.1016/j.memsci.2014.03.055]
[15]
Liu, F.; Hashim, N.A.; Liu, Y.; Abed, M.R.M.; Li, K. Progress in the production and modification of PVDF membranes. J. Membr. Sci., 2011, 375(1-2), 1-27.
[http://dx.doi.org/10.1016/j.memsci.2011.03.014]
[http://dx.doi.org/10.1016/j.memsci.2011.03.014]
[16]
Saxena, P.; Shukla, P. A comprehensive review on fundamental properties and applications of poly(vinylidene fluoride) (PVDF). Adv. Compos. Hybrid Mater., 2021, 4(1), 8-26.
[http://dx.doi.org/10.1007/s42114-021-00217-0]
[http://dx.doi.org/10.1007/s42114-021-00217-0]
[17]
Thakur, P.; Kool, A.; Hoque, N.A.; Bagchi, B.; Khatun, F.; Biswas, P.; Brahma, D.; Roy, S.; Banerjee, S.; Das, S. Superior performances of in situ synthesized ZnO/PVDF thin film based self-poled piezoelectric nanogenerator and self-charged photo-power bank with high durability. Nano Energy, 2018, 44, 456-467.
[http://dx.doi.org/10.1016/j.nanoen.2017.11.065]
[http://dx.doi.org/10.1016/j.nanoen.2017.11.065]
[18]
Sagar, R.; Gaur, M.S.; Raghav, R.K. Study of structural, thermal and piezoelectric properties of polyvinylidene fluoride –BaZrO3 nanocomposites. J. Therm. Anal. Calorim., 2022, 147(19), 10371-10381.
[http://dx.doi.org/10.1007/s10973-022-11302-x]
[http://dx.doi.org/10.1007/s10973-022-11302-x]
[19]
Bhunia, R.; Gupta, S.; Fatma, B. Prateek, Gupta, R.K.; Garg, A. Milli-watt power harvesting from dual triboelectric and piezoelectric effects of multifunctional green and robust reduced graphene oxide/P(VDF-TrFE) composite flexible films. ACS Appl. Mater. Interfaces, 2019, 11(41), 38177-38189.
[http://dx.doi.org/10.1021/acsami.9b13360] [PMID: 31580638]
[http://dx.doi.org/10.1021/acsami.9b13360] [PMID: 31580638]
[20]
Roy, K.; Ghosh, S.K.; Sultana, A.; Garain, S.; Xie, M.; Bowen, C.R.; Henkel, K. Schmeiβer, D.; Mandal, D. A self-powered wearable pressure sensor and pyroelectric breathing sensor based on GO interfaced PVDF nanofibers. ACS Appl. Nano Mater., 2019, 2(4), 2013-2025.
[http://dx.doi.org/10.1021/acsanm.9b00033]
[http://dx.doi.org/10.1021/acsanm.9b00033]
[21]
Zhang, Q.; Xia, W.; Zhu, Z.; Zhang, Z. Crystal phase of poly(vinylidene fluoride- co -trifluoroethylene) synthesized via hydrogenation of poly(vinylidene fluoride- co -chlorotrifluoroethylene). J. Appl. Polym. Sci., 2013, 127(4), 3002-3008.
[http://dx.doi.org/10.1002/app.37975]
[http://dx.doi.org/10.1002/app.37975]
[22]
Park, K.I.; Son, J.H.; Hwang, G.T.; Jeong, C.K.; Ryu, J.; Koo, M.; Choi, I.; Lee, S.H.; Byun, M.; Wang, Z.L.; Lee, K.J. Highly-efficient, flexible piezoelectric PZT thin film nanogenerator on plastic substrates. Adv. Mater., 2014, 26(16), 2514-2520.
[http://dx.doi.org/10.1002/adma.201305659] [PMID: 24523251]
[http://dx.doi.org/10.1002/adma.201305659] [PMID: 24523251]
[23]
Jain, A. K., J P.; Sharma, A.K.; Jain A., P.N R. Dielectric and piezoelectric properties of PVDF/PZT composites: A review. Polym. Eng. Sci., 2015, 55, 1589-1616.
[http://dx.doi.org/10.1002/pen.24088]
[http://dx.doi.org/10.1002/pen.24088]
[24]
Wankhade, S.H.; Tiwari, S.; Gaur, A.; Maiti, P. PVDF–PZT nanohybrid based nanogenerator for energy harvesting applications. Energy Rep., 2020, 6, 358-364.
[http://dx.doi.org/10.1016/j.egyr.2020.02.003]
[http://dx.doi.org/10.1016/j.egyr.2020.02.003]
[25]
Guan, X.; Xu, B.; Gong, J. Hierarchically architected polydopamine modified BaTiO3@P(VDF-TrFE) nanocomposite fiber mats for flexible piezoelectric nanogenerators and self-powered sensors. Nano Energy, 2020, 70, 104516.
[http://dx.doi.org/10.1016/j.nanoen.2020.104516]
[http://dx.doi.org/10.1016/j.nanoen.2020.104516]
[26]
Habibur, R.M.; Yaqoob, U.; Muhammad, S.; Uddin, A.S.M.I.; Kim, H.C. The effect of RGO on dielectric and energy harvesting properties of P(VDF-TrFE) matrix by optimizing electroactive β phase without traditional polling process. Mater. Chem. Phys., 2018, 215, 46-55.
[http://dx.doi.org/10.1016/j.matchemphys.2018.05.010]
[http://dx.doi.org/10.1016/j.matchemphys.2018.05.010]
[27]
Liu, M.R. Fabrication, Characterization and Investigation of Novel PVDF/ZnO and PVDF-TrFE/ZnO Nanocomposites with Enhanced β-. Phase and Dielectricity. Mater. Sci. Forum, 2020, 977, 277-282.
[http://dx.doi.org/10.4028/www.scientific.net/MSF.977.277]
[http://dx.doi.org/10.4028/www.scientific.net/MSF.977.277]
[28]
Shin, K.Y.; Lee, J.S.; Jang, J. Highly sensitive, wearable and wireless pressure sensor using free-standing ZnO nanoneedle/PVDF hybrid thin film for heart rate monitoring. Nano Energy, 2016, 22, 95-104.
[http://dx.doi.org/10.1016/j.nanoen.2016.02.012]
[http://dx.doi.org/10.1016/j.nanoen.2016.02.012]
[29]
Smith, M.; Kar-Narayan, S. Piezoelectric polymers: Theory, challenges and opportunities. Int. Mater. Rev., 2022, 67(1), 65-88.
[http://dx.doi.org/10.1080/09506608.2021.1915935]
[http://dx.doi.org/10.1080/09506608.2021.1915935]
[30]
Zhu, L.; Xiang, Y.; Liu, Y.; Geng, K.; Yao, R.; Li, B. Comparison of piezoelectric responses of flexible tactile sensors based on hydrothermally-grown ZnO nanorods on ZnO seed layers with different thicknesses. Sens. Actuators A Phys., 2022, 341, 113552.
[http://dx.doi.org/10.1016/j.sna.2022.113552]
[http://dx.doi.org/10.1016/j.sna.2022.113552]
[31]
Yang, T.; Xie, D.; Li, Z.; Zhu, H. Recent advances in wearable tactile sensors: Materials, sensing mechanisms, and device performance. Mater. Sci. Eng. Rep., 2017, 115, 1-37.
[http://dx.doi.org/10.1016/j.mser.2017.02.001]
[http://dx.doi.org/10.1016/j.mser.2017.02.001]
[32]
Liu, Y.; Zhang, Y.; Yang, Q.; Niu, S.; Wang, Z.L. Fundamental theories of piezotronics and piezo-phototronics. Nano Energy, 2015, 14, 257-275.
[http://dx.doi.org/10.1016/j.nanoen.2014.11.051]
[http://dx.doi.org/10.1016/j.nanoen.2014.11.051]
[33]
Yi, G.C.; Wang, C.; Park, W.I. ZnO nanorods: Synthesis, characterization and applications. Semicond. Sci. Technol., 2005, 20(4), S22-S34.
[http://dx.doi.org/10.1088/0268-1242/20/4/003]
[http://dx.doi.org/10.1088/0268-1242/20/4/003]
[34]
Yang, P.; Yan, H.; Mao, S.; Russo, R.; Johnson, J.; Saykally, R.; Morris, N.; Pham, J.; He, R.; Choi, H.J. Controlled growth of ZnO nanowires and their optical properties. Adv. Funct. Mater., 2002, 12(5), 323-331.
[http://dx.doi.org/10.1002/1616-3028(20020517)12:5<323:AID-ADFM323>3.0.CO;2-G]
[http://dx.doi.org/10.1002/1616-3028(20020517)12:5<323:AID-ADFM323>3.0.CO;2-G]
[35]
Kalpana, V.N.; Devi, R.V. A review on green synthesis, biomedical applications, and toxicity studies of ZnO NPs. Bioinorg. Chem. Appl., 2018, 2018, 3569758.
[http://dx.doi.org/10.1155/2018/3569758] [PMID: 30154832]
[http://dx.doi.org/10.1155/2018/3569758] [PMID: 30154832]
[36]
Zhang, Z.; Yuan, H.; Zhou, J.; Liu, D.; Luo, S.; Miao, Y.; Gao, Y.; Wang, J.; Liu, L.; Song, L.; Xiang, Y.; Zhao, X.; Zhou, W.; Xie, S. Growth mechanism, photoluminescence, and field-emission properties of ZnO nanoneedle arrays. J. Phys. Chem. B, 2006, 110(17), 8566-8569.
[http://dx.doi.org/10.1021/jp0568632] [PMID: 16640407]
[http://dx.doi.org/10.1021/jp0568632] [PMID: 16640407]
[37]
Mishra, Y.K.; Adelung, R. ZnO tetrapod materials for functional applications. Mater. Today, 2018, 21(6), 631-651.
[http://dx.doi.org/10.1016/j.mattod.2017.11.003]
[http://dx.doi.org/10.1016/j.mattod.2017.11.003]
[38]
Wang, Y.; Li, X.; Wang, N.; Quan, X.; Chen, Y. Controllable synthesis of ZnO nanoflowers and their morphology-dependent photocatalytic activities. Separ. Purif. Tech., 2008, 62(3), 727-732.
[http://dx.doi.org/10.1016/j.seppur.2008.03.035]
[http://dx.doi.org/10.1016/j.seppur.2008.03.035]
[39]
Karumuthil, S.C.; Rajeev, S.P.; Varghese, S. Poly(vinylidene fluoride-trifluoroethylene)-ZnO nanoparticle composites on a flexible poly(dimethylsiloxane) substrate for energy harvesting. ACS Appl. Nano Mater., 2019, 2(7), 4350-4357.
[http://dx.doi.org/10.1021/acsanm.8b02248]
[http://dx.doi.org/10.1021/acsanm.8b02248]
[40]
Li, J.; Zhao, C.; Xia, K.; Liu, X.; Li, D.; Han, J. Enhanced piezoelectric output of the PVDF-TrFE/ZnO flexible piezoelectric nanogenerator by surface modification. Appl. Surf. Sci., 2019, 463, 626-634.
[http://dx.doi.org/10.1016/j.apsusc.2018.08.266]
[http://dx.doi.org/10.1016/j.apsusc.2018.08.266]
[41]
Mohd Dahan, R.; Arshad, A.N.; Md Razif, M.H.; Mahmud Zohdi, N.S.; Mahmood, M.R. Structural and electrical properties of PVDF-TrFE/ZnO bilayer and filled PVDF-TrFE/ZnO single layer nanocomposite films. Adv. Mater. Process. Technol., 2017, 3(3), 300-307.
[http://dx.doi.org/10.1080/2374068X.2017.1330630]
[http://dx.doi.org/10.1080/2374068X.2017.1330630]
[42]
Arularasu, M.V.; Harb, M.; Vignesh, R.; Rajendran, T.V.; Sundaram, R. PVDF/ZnO hybrid nanocomposite applied as a resistive humidity sensor. Surf. Interfaces, 2020, 21, 100780.
[http://dx.doi.org/10.1016/j.surfin.2020.100780]
[http://dx.doi.org/10.1016/j.surfin.2020.100780]
[43]
Devi, P.I.; Ramachandran, K. Dielectric studies on hybridised PVDF–ZnO nanocomposites. J. Exp. Nanosci., 2011, 6(3), 281-293.
[http://dx.doi.org/10.1080/17458080.2010.497947]
[http://dx.doi.org/10.1080/17458080.2010.497947]
[44]
Liu, M.; Liu, Y.; Zhou, L. Novel flexible PVDF-TrFE and PVDF-TrFE/ZnO pressure sensor: Fabrication, characterization and investigation. Micromachines, 2021, 12(6), 602.
[http://dx.doi.org/10.3390/mi12060602] [PMID: 34071010]
[http://dx.doi.org/10.3390/mi12060602] [PMID: 34071010]
[45]
Han, J.; Li, D.; Zhao, C.; Wang, X.; Li, J.; Wu, X. Highly sensitive impact sensor based on PVDF-TrFE/Nano-ZnO composite thin film. Sensors, 2019, 19(4), 830.
[http://dx.doi.org/10.3390/s19040830] [PMID: 30781598]
[http://dx.doi.org/10.3390/s19040830] [PMID: 30781598]
[46]
He, H.; Fu, Y.; Zang, W.; Wang, Q.; Xing, L.; Zhang, Y.; Xue, X. A flexible self-powered T-ZnO/PVDF/fabric electronic-skin with multi-functions of tactile-perception, atmosphere-detection and self-clean. Nano Energy, 2017, 31, 37-48.
[http://dx.doi.org/10.1016/j.nanoen.2016.11.020]
[http://dx.doi.org/10.1016/j.nanoen.2016.11.020]
[47]
Mohanty, P.; Mahapatra, R.; Padhi, P.; Ramana, C.; Mishra, D.K. Ultrasonic cavitation: An approach to synthesize uniformly dispersed metal matrix nanocomposites—A review. Nano-Struct. Nano-Objects, 2020, 23, 100475.
[http://dx.doi.org/10.1016/j.nanoso.2020.100475]
[http://dx.doi.org/10.1016/j.nanoso.2020.100475]
[48]
Tan, V.; Gogos, C.G. Flow-induced crystallization of linear polyethylene above its normal melting point. Polym. Eng. Sci., 1976, 16(7), 512-525.
[http://dx.doi.org/10.1002/pen.760160709]
[http://dx.doi.org/10.1002/pen.760160709]
[49]
Zhang, Y.; Lu, G.; Chen, M.; Liu, Y.; Yao, R. Flexible self-powered tactile sensors based on hydrothermally grown ZnO nanorods. IEEE Sens. J., 2022, 22(13), 12613-12621.
[http://dx.doi.org/10.1109/JSEN.2022.3176655]
[http://dx.doi.org/10.1109/JSEN.2022.3176655]
[50]
Baniasadi, M.; Xu, Z.; Hong, S.; Naraghi, M.; Minary-Jolandan, M. Thermo-electromechanical behavior of piezoelectric nanofibers. ACS Appl. Mater. Interfaces, 2016, 8(4), 2540-2551.
[http://dx.doi.org/10.1021/acsami.5b10073] [PMID: 26795238]
[http://dx.doi.org/10.1021/acsami.5b10073] [PMID: 26795238]
[51]
Mandal, D.; Henkel, K.; Schmeißer, D. Improved performance of a polymer nanogenerator based on silver nanoparticles doped electrospun P(VDF–HFP) nanofibers. Phys. Chem. Chem. Phys., 2014, 16(22), 10403-10407.
[http://dx.doi.org/10.1039/c3cp55238a] [PMID: 24733435]
[http://dx.doi.org/10.1039/c3cp55238a] [PMID: 24733435]
[52]
Gregorio, R., Jr Determination of the α β and γ crystalline phases of poly(vinylidene fluoride) films prepared at different conditions. J. Appl. Polym. Sci., 2006, 100(4), 3272-3279.
[http://dx.doi.org/10.1002/app.23137]
[http://dx.doi.org/10.1002/app.23137]
[53]
Ke, K.; Pötschke, P.; Jehnichen, D.; Fischer, D.; Voit, B. Achieving β-phase poly(vinylidene fluoride) from melt cooling: Effect of surface functionalized carbon nanotubes. Polymer, 2014, 55(2), 611-619.
[http://dx.doi.org/10.1016/j.polymer.2013.12.014]
[http://dx.doi.org/10.1016/j.polymer.2013.12.014]
[54]
Pratihar, S.; Medda, S.K.; Sen, S.; Devi, P.S. Tailored piezoelectric performance of self‐polarized pvdf‐ZnO composites by optimization of aspect ratio of ZnO nanorods. Polym. Compos., 2020, 41(8), 3351-3363.
[http://dx.doi.org/10.1002/pc.25624]
[http://dx.doi.org/10.1002/pc.25624]
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