Abstract
Monitoring the physiological signals of people by using wearable sensors attached to the skin while they go about their daily routine is a practical approach to prevent diseases and monitor people’s health status. However, conventional monitoring devices are bulky, their signals are corrupted by the noise generated by external sources, and they are prone to mechanical failure, which hinder their practical use. Herein, a mechanically durable biomaterial-based arterial pulse thin-film sensor is developed for real-time monitoring of cyclic physiological signals. A hierarchical layered material (rGO/SF/CNC) comprising reduced graphene oxide (rGO), silk fibroin (SF), and cellulose nanocrystals (CNCs) is fabricated using the spin-assisted layer-by-layer (SA-LbL) technique and thermal reduction. Thermal reduction is performed to tailor the defects in rGO, which significantly enhances its mechanical robustness and bending properties, as well as in-plane stress sensitivity, owing to a change in conductivity. The thin-film (thickness: 40.9 nm) sensor has a rapid response time (69 ms) and excellent durability exceeding 8000 cycles. Moreover, it is insensitive to strain in the orthogonal direction, which significantly reduces the noise level and dramatically increases its sensitivity. The sensor’s suitability for practical use as an arterial pulse sensor for monitoring physiological signals is demonstrated. The developed thin-film flexible stress sensor has the potential to contribute toward the improvement of wearable healthcare monitoring devices and human–machine interaction.
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References
Acik M, Lee G, Mattevi C, Pirkle A, Wallace RM, Chhowalla M, Cho K, Chabal Y (2011) The role of oxygen during thermal reduction of graphene oxide studied by infrared absorption spectroscopy. J Phys Chem C 115:19761–19781. https://doi.org/10.1021/jp2052618
Akhavan O (2010) The effect of heat treatment on formation of graphene thin films from graphene oxide nanosheets. Carbon 48:509–519. https://doi.org/10.1016/j.carbon.2009.09.069
Attarpour A, Mahnam A, Aminitabar A, Samani H (2019) Cuff-less continuous measurement of blood pressure using wrist and fingertip photo-plethysmograms: evaluation and feature analysis. Biomed Signal Process Control 49:212–220. https://doi.org/10.1016/j.bspc.2018.12.006
Borini S, White R, Wei D, Astley M, Haque S, Spigone E, Harris N, Kivioja J, Ryhanen T (2013) Ultrafast graphene oxide humidity sensors. ACS Nano 7:11166–11173. https://doi.org/10.1021/nn404889b
Boutry CM, Beker L, Kaizawa Y, Vassos C, Tran H, Hinckley AC, Pfattner R, Niu S, Li J, Claverie J, Wang Z, Chang J, Fox PM, Bao Z (2019) Biodegradable and flexible arterial-pulse sensor for the wireless monitoring of blood flow. Nat Biomed Eng 3:47–57. https://doi.org/10.1038/s41551-018-0336-5
Chen W, Yan L, Bangal PR (2010a) Chemical reduction of graphene oxide to graphene by sulfur-containing compounds. J Phys Chem C 114:19885–19890. https://doi.org/10.1021/jp107131v
Chen W, Yan L, Bangal PR (2010b) Preparation of graphene by the rapid and mild thermal reduction of graphene oxide induced by microwaves. Carbon 48:1146–1152. https://doi.org/10.1016/j.carbon.2009.11.037
Chen J, Liu H, Wang W, Nabulsi N, Zhao W, Kim JY, Kwon M-K, Ryou JH (2019) High durable, biocompatible, and flexible piezoelectric pulse sensor using single-crystalline III‐N thin film. Adv Funct Mater 29:1903162. https://doi.org/10.1002/adfm.201903162
Cheng Q, Duan J, Zhang Q, Jiang L (2015) Learning from nature: constructing integrated graphene-based artificial nacre. ACS Nano 9:2231–2234. https://doi.org/10.1021/acsnano.5b01126
Cheng J, Xu Y, Song R, Liu Y, Li C, Chen X (2021) Prediction of arterial blood pressure waveforms from photoplethysmogram signals via fully convolutional neural networks. Comput Biol Med 138:104877. https://doi.org/10.1016/j.compbiomed.2021.104877
Chhetry A, Kim J, Yoon H, Park JY (2019) Ultrasensitive interfacial capacitive pressure sensor based on a randomly distributed microstructured iontronic film for wearable applications. ACS Appl Mater Interfaces 11:3438–3449. https://doi.org/10.1021/acsami.8b17765
Cho H, Lee H, Lee S, Kim S (2021a) Reduced graphene oxide-based wearable and bio-electrolyte triggered pressure sensor with tunable sensitivity. Ceram Int 47:17702–17710. https://doi.org/10.1016/j.ceramint.2021.03.090
Cho H, Shakil A, Polycarpou AA, Kim S (2021b) Enabling selectively tunable mechanical properties of graphene oxide/silk fibroin/cellulose nanocrystal bionanofilms. ACS Nano 15:19546–19558. https://doi.org/10.1021/acsnano.1c06573
Cho H, Lee J, Hwang H, Hwang W, Kim J-G, Kim S (2022) Mechanical properties of graphene oxide–silk fibroin bionanofilms via nanoindentation experiments and finite element analysis. Friction 10:282–295. https://doi.org/10.1007/s40544-021-0490-8
Dawson EA, Black MA, Pybis J, Cable NT, Green DJ (2009) The impact of exercise on derived measures of central pressure and augmentation index obtained from the SphygmoCor device. J Appl Physiol 106:1896–1901. https://doi.org/10.1152/japplphysiol.91564.2008
Dubin S, Gilje S, Wang K, Tung VC, Cha K, Hall AS, Farrar J, Varshneya R, Yang Y, Kaner RB (2010) A one-step, solvothermal reduction method for producing reduced graphene oxide dispersions in organic solvents. ACS Nano 4:3845–3852. https://doi.org/10.1021/nn100511a
Eda G, Chhowalla M (2010) Chemically derived graphene oxide: towards large-area thin-film electronics and optoelectronics. Adv Mater 22:2392–2415. https://doi.org/10.1002/adma.200903689
Ge G, Cai Y, Dong Q, Zhang Y, Shao J, Huang W, Dong X (2018) A flexible pressure sensor based on rGO/polyaniline wrapped sponge with tunable sensitivity for human motion detection. Nanoscale 10:10033–10040. https://doi.org/10.1039/C8NR02813C
Gil ES, Frankowski DJ, Bowman MK, Gozen AO, Hudson SM, Spontak RJ (2006) Mixed protein blends composed of gelatin and bombyx mori silk fibroin: Effects of solvent-induced crystallization and composition. Biomacromolecules 7:728–735. https://doi.org/10.1021/bm050622i
Habibi Y, Lucia LA, Rojas OJ (2010) Cellulose nanocrystals: Chemistry, self-assembly, and applications. Chem Rev 110:3479–3500. https://doi.org/10.1021/cr900339w
He J, Xiao P, Lu W, Shi J, Zhang L, Liang Y, Pan C, Kuo S-W, Chen T (2019) A universal high accuracy wearable pulse monitoring system via high sensitivity and large linearity graphene pressure sensor. Nano Energy 59:422–433. https://doi.org/10.1016/j.nanoen.2019.02.036
Hu X, Kaplan D, Cebe P (2007) Effect of water on the thermal properties of silk fibroin. Thermochim Acta 461:137–144. https://doi.org/10.1016/j.tca.2006.12.011
Hu K, Gupta MK, Kulkarni DD, Tsukruk VV (2013) Ultra-robust graphene oxide-silk fibroin nanocomposite membranes. Adv Mater 25:2301–2307. https://doi.org/10.1002/adma.201300179
Hu K, Xiong R, Guo H, Ma R, Zhang S, Wang ZL, Tsukruk VV (2016) Self-powered electronic skin with biotactile selectivity. Adv Mater 28:3549–3556. https://doi.org/10.1002/adma.201506187
Huang C-B, Witomska S, Aliprandi A, Stoeckel MA, Bonini M, Ciesielski A, Samorì P (2019) Molecule-graphene hybrid materials with tunable mechanoresponse: highly sensitive pressure sensors for health monitoring. Adv Mater 31:1804600. https://doi.org/10.1002/adma.201804600
Hummers WS, Offeman RE (1958) Preparation of graphitic oxide. J Am Chem Soc 80:1339–1339. https://doi.org/10.1021/ja01539a017
Jiang C, Tsukruk VV (2006) Freestanding nanostructures via layer-by-layer assembly. Adv Mater 18:829–840. https://doi.org/10.1002/adma.200502444
Jiang C, Markutsya S, Tsukruk VV (2004) Collective and individual plasmon resonances in nanoparticle films obtained by spin-assisted layer-by-layer assembly. Langmuir 20:882–890. https://doi.org/10.1021/la0355085
Jung HH, Song J, Nie S, Jung HN, Kim MS, Jeong JW, Song YM, Song J, Jang KI (2018) Thin metallic heat sink for interfacial thermal management in biointegrated optoelectronic devices. Adv Mater Technol 3:1800159. https://doi.org/10.1002/admt.201800159
Kang M, Kim J, Jang B, Chae Y, Kim JH, Ahn JH (2017) Graphene-based three-dimensional capacitive touch sensor for wearable electronics. ACS Nano 11:7950–7957. https://doi.org/10.1021/acsnano.7b02474
Kedambaimoole V, Kumar N, Shirhatti V, Nuthalapati S, Kumar S, Nayak MM, Sen P, Akinwande D, Rajanna K (2021) Reduced graphene oxide tattoo as wearable proximity sensor. Adv Electron Mater 7:2001214. https://doi.org/10.1002/aelm.202001214
Kim S, Xiong R, Tsukruk VV (2016) Probing flexural properties of cellulose nanocrystal–graphene nanomembranes with force spectroscopy and bulging test. Langmuir 32:5383–5393. https://doi.org/10.1021/acs.langmuir.6b01079
Koh L-D, Cheng Y, Teng C-P, Khin Y-W, Loh X-J, Tee S-Y, Low M, Ye E, Yu H-D, Zhang Y-W, Han M-Y (2015) Structures, mechanical properties and applications of silk fibroin materials. Prog Polym Sci 46:86–110. https://doi.org/10.1016/j.progpolymsci.2015.02.001
Kohara K, Tabara Y, Oshiumi A, Miyawaki Y, Kobayashi T, Miki T (2005) Radial augmentation index: a useful and easily obtainable parameter for vascular aging. Am J Hypertens 18:11–14. https://doi.org/10.1016/j.amjhyper.2004.10.010
Kulkarni DD, Kim S, Chyasnavichyus M, Hu K, Fedorov AG, Tsukruk VV (2014) Chemical reduction of individual graphene oxide sheets as revealed by electrostatic force microscopy. J Am Chem Soc 136:6546–6549. https://doi.org/10.1021/ja5005416
Le X, Liu Y, Peng L, Pang J, Xu Z, Gao C, Xie J (2019) Surface acoustic wave humidity sensors based on uniform and thickness controllable graphene oxide thin films formed by surface tension. Microsyst Nanoeng 5:36. https://doi.org/10.1038/s41378-019-0075-0
Lee C, Wei X, Kysar JW, Hone J (2008) Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science 321:385–388. https://doi.org/10.1126/science.1157996
Lee S, Reuveny A, Reeder J, Lee S, Jin H, Liu Q, Yokota T, Sekitani T, Isoyama T, Abe Y, Suo Z, Someya TA (2016) A transparent bending-insensitive pressure sensor. Nat Nanotechnol 11:472–478. https://doi.org/10.1038/nnano.2015.324
Lee J, Pyo S, Kwon DS, Jo E, Kim W, Kim J (2019) Ultrasensitive strain sensor based on separation of overlapped carbon nanotubes. Small 15:1805120. https://doi.org/10.1002/smll.201805120
Liang Y, Elgendi M, Chen Z, Ward R (2018) An optimal filter for short photoplethysmogram signals. Sci Data 5:180076. https://doi.org/10.1038/sdata.2018.76
Liu Y, Meng F, Zhou Y, Mugo SM, Zhang Q (2019) Graphene oxide films prepared using gelatin nanofibers as wearable sensors for monitoring cardiovascular health. Adv Mater Technol 4:1900540. https://doi.org/10.1002/admt.201900540
Luo N, Dai W, Li C, Zhou Z, Lu L, Poon CC, Chen S-C, Zhang Y, Zhao N (2016) Flexible piezoresistive sensor patch enabling ultralow power cuffless blood pressure measurement. Adv Funct Mater 26:1178–1187. https://doi.org/10.1002/adfm.201504560
Mao L, Park H, Soler-Crespo RA, Espinosa HD, Han TH, Nguyen ST, Huang J (2019) Stiffening of graphene oxide films by soft porous sheets. Nat Commun 10:3677. https://doi.org/10.1038/s41467-019-11609-8
McConney ME, Singamaneni S, Tsukruk VV (2010) Probing soft matter with the atomic force microscopies: imaging and force spectroscopy. Polym Rev 50:235–286. https://doi.org/10.1080/15583724.2010.493255
Motta A, Fambri L, Migliaresi C (2002) Regenerated silk fibroin films: thermal and dynamic mechanical analysis. Macromol Chem Phys 203:1658–1665.
Munir S, Jiang B, Guilcher A, Brett S, Redwood S, Marber M, Chowienczyk P (2008) Exercise reduces arterial pressure augmentation through vasodilation of muscular arteries in humans. Am J Physiol-Heart Circul Physiol 294:H1645–H1650. https://doi.org/10.1152/ajpheart.01171.2007
Nichols W (2005) Clinical measurement of arterial stiffness obtained from noninvasive pressure waveforms. Am J Hypertens 18:3–10. https://doi.org/10.1016/j.amjhyper.2004.10.009
Ouyang H, Tian J, Sun G, Zou Y, Liu Z, Li H, Zhao L, Shi B, Fan Y, Fan Y, Wang ZL, Li Z (2017) Self-powered pulse sensor for antidiastole of cardiovascular disease. Adv Mater 29:1703456. https://doi.org/10.1002/adma.201703456
Park OK, Hahm MG, Lee S, Joh H-I, Na S-I, Vajtai R, Lee JH, Ku B-C, Ajayan PM (2012) In situ synthesis of thermochemically reduced graphene oxide conducting nanocomposites. Nano Lett 12:1789–1793. https://doi.org/10.1021/nl203803d
Park DY, Joe DJ, Kim DH, Park H, Han JH, Jeong CK, Park H, Park JG, Joung B, Lee KJ (2017) Self-powered real‐time arterial pulse monitoring using ultrathin epidermal piezoelectric sensors. Adv Mater 29:1702308. https://doi.org/10.1002/adma.201702308
Pu X, An S, Tang Q, Guo H, Hu C (2021) Wearable triboelectric sensors for biomedical monitoring and human-machine interface. iScience 24:102027. https://doi.org/10.1016/j.isci.2020.102027
Ram MR, Madhav KV, Krishna EH, Komalla NR, Reddy KA (2012) A novel approach for motion artifact reduction in PPG signals based on AS-LMS adaptive filter. IEEE Trans Instrum Meas 61:1445–1457. https://doi.org/10.1109/TIM.2011.2175832
Reşit Kavsaoğlu A, Polat K, Recep Bozkurt M (2014) A novel feature ranking algorithm for biometric recognition with PPG signals. Comput Biol Med 49:1–14. https://doi.org/10.1016/j.compbiomed.2014.03.005
Roth GA, Huffman MD, Moran AE, Feigin V, Mensah GA, Naghavi M, Murray CJ (2015) Global and regional patterns in cardiovascular mortality from 1990 to 2013. Circulation 132:1667–1678. https://doi.org/10.1161/CIRCULATIONAHA.114.008720
Ruth SRA, Feig VR, Tran H, Bao Z (2020) Microengineering pressure sensor active layers for improved performance. Adv Funct Mater 30:2003491. https://doi.org/10.1002/adfm.202003491
Sahoo S, Khurana G, Barik SK, Dussan S, Barrionuevo D, Katiyar RS (2013) In situ raman studies of electrically reduced graphene oxide and its field-emission properties. J Phys Chem C 117:5485–5491. https://doi.org/10.1021/jp400573w
Schniepp HC, Kudin KN, Li J-L, Prud’homme RK, Car R, Saville DA, Aksay IA (2008) Bending properties of single functionalized graphene sheets probed by atomic force microscopy. ACS Nano 2:2577–2584. https://doi.org/10.1021/nn800457s
Sellinger A, Weiss PM, Nguyen A, Lu Y, Assink RA, Gong W, Brinker CJ (1998) Continuous self-assembly of organic–inorganic nanocomposite coatings that mimic nacre. Nature 394:256–260. https://doi.org/10.1038/28354
Seok Jo H, An S, Kwon H-J, Yarin AL, Yoon SS (2020) Transparent body-attachable multifunctional pressure, thermal, and proximity sensor and heater. Sci Rep 10:2701. https://doi.org/10.1038/s41598-020-59450-0
Shakil A, Kim S, Polycarpou AA (2022) Creep behavior of graphene oxide, silk fibroin, and cellulose nanocrystal bionanofilms. Adv Mater Interfaces 9:2101640. https://doi.org/10.1002/admi.202101640
Song M, Chung J, Chung S-H, Cha K, Heo D, Kim S, Hwang PT, Kim D, Koo B, Hong J (2022) Semisolid-lubricant-based ball-bearing triboelectric nanogenerator for current amplification, enhanced mechanical lifespan, and thermal stabilization. Nano Energy 93:106816. https://doi.org/10.1016/j.nanoen.2021.106816
Suk JW, Piner RD, An J, Ruoff RS (2010) Mechanical properties of monolayer graphene oxide. ACS Nano 4:6557–6564. https://doi.org/10.1021/nn101781v
Tadepalli S, Hamper H, Park SH, Cao S, Naik RR, Singamaneni S (2016) Adsorption behavior of silk fibroin on amphiphilic graphene oxide. ACS Biomater Sci Eng 2:1084–1092. https://doi.org/10.1021/acsbiomaterials.6b00232
Tan C, Dong Z, Li Y, Zhao H, Huang X, Zhou Z, Jiang J-W, Long Y-Z, Jiang P, Zhang T-Y, Sun B (2020) A high performance wearable strain sensor with advanced thermal management for motion monitoring. Nat Commun 11:3530. https://doi.org/10.1038/s41467-020-17301-6
Tang Y, Zhao Z, Hu H, Liu Y, Wang X, Zhou S, Qiu J (2015) Highly stretchable and ultrasensitive strain sensor based on reduced graphene oxide microtubes–elastomer composite. ACS Appl Mater Interfaces 7:27432–27439. https://doi.org/10.1021/acsami.5b09314
Temko A (2017) Accurate heart rate monitoring during physical exercises using PPG. IEEE Trans Biomed Eng 64:2016–2024. https://doi.org/10.1109/TBME.2017.2676243
Venugopal K, Panchatcharam P, Chandrasekhar A, Shanmugasundaram V (2021) Comprehensive review on triboelectric nanogenerator based wrist pulse measurement: Sensor fabrication and diagnosis of arterial pressure. ACS Sens 6:1681–1694. https://doi.org/10.1021/acssensors.0c02324
Wang Y, Ma R, Hu K, Kim S, Fang G, Shao Z, Tsukruk VV (2016a) Dramatic enhancement of graphene oxide/silk nanocomposite membranes: increasing toughness, strength, and Young’s modulus via annealing of interfacial structures. ACS Appl Mater Interfaces 8:24962–24973. https://doi.org/10.1021/acsami.6b08610
Wang Z, Wang S, Zeng J, Ren X, Chee AJ, Yiu BY, Chung WC, Yang Y, Yu AC, Roberts RC, Tsang AC, Chow KW, Chan PK (2016b) High sensitivity, wearable, piezoresistive pressure sensors based on irregular microhump structures and its applications in body motion sensing. Small 12:3827–3836. https://doi.org/10.1002/smll.201601419
Wang J, Zhu Y, Wu Z, Zhang Y, Lin J, Chen T, Liu H, Wang F, Sun L (2022) Wearable multichannel pulse condition monitoring system based on flexible pressure sensor arrays. Microsyst Nanoeng 8:16. https://doi.org/10.1038/s41378-022-00349-3
Wen Y, Wu M, Zhang M, Li C, Shi G (2017) Topological design of ultrastrong and highly conductive graphene films. Adv Mater 29:1702831. https://doi.org/10.1002/adma.201702831
Wen D-L, Sun D-H, Huang P, Huang W, Su M, Wang Y, Han M-D, Kim B, Brugger J, Zhang H-X (2021) Recent progress in silk fibroin-based flexible electronics. Microsyst Nanoeng 7:35. https://doi.org/10.1038/s41378-021-00261-2
Wu X, Han Y, Zhang X, Lu C (2016) Highly sensitive, stretchable, and wash-durable strain sensor based on ultrathin conductive Layer@Polyurethane yarn for tiny motion monitoring. ACS Appl Mater Interfaces 8:9936–9945. https://doi.org/10.1021/acsami.6b01174
Xie W, Tadepalli S, Park SH, Kazemi-Moridani A, Jiang Q, Singamaneni S, Lee J-H (2018) Extreme mechanical behavior of nacre-mimetic graphene-oxide and silk nanocomposites. Nano Lett 18:987–993. https://doi.org/10.1021/acs.nanolett.7b04421
Xin W, Xiao H, Kong X-Y, Chen J, Yang L, Niu B, Qian Y, Teng Y, Jiang L, Wen L (2020) Biomimetic nacre-like silk-crosslinked membranes for osmotic energy harvesting. ACS Nano 14:9701–9710. https://doi.org/10.1021/acsnano.0c01309
Xiong R, Hu K, Grant AM, Ma R, Xu W, Lu C, Zhang X, Tsukruk VV (2016) Ultrarobust transparent cellulose nanocrystal-graphene membranes with high electrical conductivity. Adv Mater 28:1501–1509. https://doi.org/10.1002/adma.201504438
Xiong R, Kim HS, Zhang L, Korolovych VF, Zhang S, Yingling YG, Tsukruk VV (2018) Wrapping nanocellulose nets around graphene oxide sheets. Angew Chem Int Edit 57:8508–8513. https://doi.org/10.1002/anie.201803076
Xu H, Lv Y, Qiu D, Zhou Y, Zeng H, Chu Y (2019a) An ultra-stretchable, highly sensitive and biocompatible capacitive strain sensor from an ionic nanocomposite for on-skin monitoring. Nanoscale 11:1570–1578. https://doi.org/10.1039/C8NR08589G
Xu M, Li F, Zhang Z, Shen T, Qi J (2019b) Piezoresistive sensors based on rGO 3D microarchitecture: coupled properties tuning in local/integral deformation. Adv Electron Mater 5:1800461. https://doi.org/10.1002/aelm.201800461
Yamada T, Hayamizu Y, Yamamoto Y, Yomogida Y, Izadi-Najafabadi A, Futaba DN, Hata K (2011) A stretchable carbon nanotube strain sensor for human-motion detection. Nat Nanotechnol 6:296–301. https://doi.org/10.1038/nnano.2011.36
Yang R, Qin Y, Dai L, Wang ZL (2009) Power generation with laterally packaged piezoelectric fine wires. Nat Nanotechnol 4:34–39. https://doi.org/10.1038/nnano.2008.314
Yang JC, Kim J-O, Oh J, Kwon SY, Sim JY, Kim DW, Choi HB, Park S (2019) Microstructured porous pyramid-based ultrahigh sensitive pressure sensor insensitive to strain and temperature. ACS Appl Mater Interfaces 11:19472–19480. https://doi.org/10.1021/acsami.9b03261
Yin K, Li H, Xia Y, Bi H, Sun J, Liu Z, Sun L (2011) Thermodynamic and kinetic analysis of low temperature thermal reduction of graphene oxide. Nanomicro Lett 3:51–55. https://doi.org/10.1007/BF03353652
Yin B, Wen Y, Hong T, Xie Z, Yuan G, Ji Q, Jia H (2017) Highly stretchable, ultrasensitive, and wearable strain sensors based on facilely prepared reduced graphene oxide woven fabrics in an ethanol flame. ACS Appl Mater Interfaces 9:32054–32064. https://doi.org/10.1021/acsami.7b09652
Zandiatashbar A, Lee G-H, An SJ, Lee S, Mathew N, Terrones M, Hayashi T, Picu CR, Hone J, Koratkar N (2014) Effect of defects on the intrinsic strength and stiffness of graphene. Nat Commun 5:3186. https://doi.org/10.1038/ncomms4186
Zhang S, Geryak R, Geldmeier J, Kim S, Tsukruk VV (2017) Synthesis, assembly, and applications of hybrid nanostructures for biosensing. Chem Rev 117:12942–13038. https://doi.org/10.1021/acs.chemrev.7b00088
Zhang Q, Wang Y, Li D, Xie J, Tao R, Luo J, Dai X, Torun H, Wu Q, Ng WP (2022) Flexible multifunctional platform based on piezoelectric acoustics for human–machine interaction and environmental perception. Microsyst Nanoeng 8:99. https://doi.org/10.1038/s41378-022-00402-1
Zhou G, Shao Z, Knight DP, Yan J, Chen X (2009) Silk fibers extruded artificially from aqueous solutions of regenerated bombyx mori silk fibroin are tougher than their natural counterparts. Adv Mater 21:366–370. https://doi.org/10.1002/adma.200800582
Zhu HT, Zhan LW, Dai Q, Xu B, Chen Y, Lu YQ, Xu F (2021) Self-assembled wavy optical microfiber for stretchable wearable sensor. Adv Opt Mater 9:2002206. https://doi.org/10.1002/adom.202002206
Acknowledgments
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) [Grant No. NRF-2021R1A2C4001717] and National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [Grant No. NRF-2021R1A4A3030268].
Funding
This work was supported by National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) [Grant No. NRF-2021R1A2C4001717], National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [Grant No. NRF-2021R1A4A3030268], and the Air Force Office of Scientific Research (AFOSR) [Grant No. FA9550-20-1-0305].
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Cho, H., Lee, G., Tsukruk, V.V. et al. Reduced graphene oxide/silk fibroin/cellulose nanocrystal-based wearable sensors with high efficiency and durability for physiological monitoring. Cellulose 30, 6435–6456 (2023). https://doi.org/10.1007/s10570-023-05289-3
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DOI: https://doi.org/10.1007/s10570-023-05289-3