Thermo-e-skin: Functional Bionic Engineering to Achieve Thermoregulation and Thermosensation

Electronic skin (e-skin) has broad application scenarios, including wearable technology, human-computer interfaces, smart prosthetics, and medical diagnosis, due to its ability to mimic human skin and offer versatile sensing capabilities. However, the state-of-art thermosensation is insufficient for comprehensive environmental perception. Furthermore, traditional e-skins cannot regulate temperature, like the human body with the isothermal function. This thesis conducts a systematic investigation of thermo-e-skin with both thermoregulation and thermosensation functions.

Two types of thermoregulation have been proposed, i.e. single-mode thermoregulation e-skin (S-thermo-e-skin) and dual-mode thermoregulation e-skin (D-thermo-e-skin). The S-thermo-e-skin involved a flexible thermoelectric device and a heat sink made of a phase change material, enabling the e-skin to maintain the isothermal function in both hot and chilly environments. The S-thermo-e-skin has a good isothermal function, maintaining a surface temperature of 35 °C in a broad environment with a temperature range of 10-45 °C. The effective time in the isothermal state of 35 °C could be over 2 hours in the mild environment with 10-30 °C, while decreased to 1.5 h and 0.75 h under the ambient temperature of 40 and 45 °C, respectively. The energy cost to maintain the isothermal state is a careful measurement, showing the lowest value of 14.22 mW/cm2 within the thermoneutral zone of 35 °C. Furthermore, the D-thermo-e-skin is functionalized with the active mode of flexible thermoelectric thermoregulation layers and the passive mode of ionic hydrogel’s evaporation/regeneration layer. The ionic hydrogel mimics the function of the bionic sweat gland. The D-thermo-e-skin significantly increased the effective time of 35 °C -isothermal-state, e.g. increased from 2h to 4.2 h under ambient temperature 40 °C. Furthermore, the e-skin's hygroscopic properties allowed it to return to its initial state within 4 hours when exposed to 90% humidity, enabling reusability. Both the S-thermo-e-skin and D-thermo-e-skin have a quick response as the e-skin as the environment changes.

A new heat-source-identification sensor was designed by using the capacitance response behavior of the methoxy poly (ethylene glycol) acrylate ionic gel. The ionic-gel sensor exhibits an impressive ultra-wide temperature range of -20 °C to 180 °C and displays a highly linear response to temperature stimuli (R2 = 0.993), and a temperature measurement accuracy of better than 0.005 °C. Moreover, the ionic-gel sensor has temperature-sensitive ion relaxation time and pressure-sensitive capacitance, which provides an effective to decouple the temperature and pressure signals. Furthermore, the ionic-gel sensor also shows proximity sense with a negative capacitance response. It was experimentally verified that the ionic sensor could identify the heat exchange modes, encompassing thermal radiation, thermal convection, and thermal conduction, by using the ion relaxation time and capacitance response. The heat-source-identification well mimics the thermosensation of human skin. Moreover, the integration of thermoregulation and thermosensation was conducted. The integrated thermo-e-skin successfully combines thermosensation, heat-source-identification, signal feedback, and thermoregulation, demonstrating a bionic thermo-sensory capability. This thesis provides a systematic solution to mimic the thermoregulation and thermosensation of human skin, which would has significant impact on the field of thermo-e-skin.

1. Chortos A, Liu J, Bao Z. Pursuing prosthetic electronic skin. Nature materials. 2016; 15(9):937-950.
2. Abraira VE, Ginty DD. The sensory neurons of touch. Neuron. 2013; 79(4):618-639.
3. Hammock ML, Chortos A, Tee BCK, Tok JBH, Bao Z. 25th anniversary article: The evolution of electronic skin (e-skin): A brief history, design considerations, and recent progress. Advanced Materials. 2013; 25(42):5997-6037.
4. Lee Y, Park J, Choe A, Cho S, Kim J, Ko H. Mimicking human and biological skins for multifunctional skin electronics. Advanced Functional Materials. 2020; 30(20) : 1904523.
5. Oh JY, Bao Z. Second skin enabled by advanced electronics. Advanced Science. 2019; 6(11) : 1900186.
6. Wang M, Luo Y, Wang Tet al. Artificial skin perception. Advanced Materials. 2021; 33(19) : 2003014.
7. Kim JJ, Wang Y, Wang H, Lee S, Yokota T, Someya T. Skin electronics: Next-generation device platform for virtual and augmented reality. Advanced Functional Materials. 2021; 31(39) : 2009602.
8. Liu Y, Pharr M, Salvatore GA. Lab-on-skin: A review of flexible and stretchable electronics for wearable health monitoring. Acs Nano. 2017; 11(10):9614-9635.9. Wang S, Oh JY, Xu J, Tran H, Bao Z. Skin-inspired electronics: An emerging paradigm. Accounts of Chemical Research. 2018; 51(5):1033-1045.
10. Costa JC, Spina F, Lugoda P, Garcia-Garcia L, Roggen D, Munzenrieder N. Flexible sensors-from materials to applications. Technologies. 2019; 7(2) : 35.
11. Yuan Y, Liu B, Li Het al. Flexible wearable sensors in medical monitoring. Biosensors-Basel. 2022; 12(12) : 1069.
12. Liu M, Pu X, Jiang Cet al. Large‐area all‐textile pressure sensors for monitoring human motion and physiological signals. Advanced materials. 2017; 29(41):1703700.
13. Zhang X, Chen J, He J, Bai Y, Zeng H. Mussel-inspired adhesive and conductive hydrogel with tunable mechanical properties for wearable strain sensors. Journal of Colloid and Interface Science. 2021; 585:420-432.
14. Joh H, Lee SW, Seong M, Lee WS, Oh SJ. Engineering the charge transport of ag nanocrystals for highly accurate, wearable temperature sensors through all‐solution processes. Small. 2017; 13(24):1700247.
15. Chen H, Song Y, Guo Het al. Hybrid porous micro structured finger skin inspired self-powered electronic skin system for pressure sensing and sliding detection. Nano Energy. 2018; 51:496-503.
16. Lee H, Choi TK, Lee YBet al. A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy. Nature nanotechnology. 2016; 11(6):566-572.
17. Bandodkar AJ, Jia W, Yardımcı C, Wang X, Ramirez J, Wang J. Tattoo-based noninvasive glucose monitoring: A proof-of-concept study. Analytical chemistry. 2015; 87(1):394-398.
18. Pang Y, Jian J, Tu Tet al. Wearable humidity sensor based on porous graphene network for respiration monitoring. Biosensors and Bioelectronics. 2018; 116:123-129.
19. Zhao J, Guo H, Pang YKet al. Flexible organic tribotronic transistor for pressure and magnetic sensing. ACS nano. 2017; 11(11):11566-11573.
20. Craig AD. Pain mechanisms: Labeled lines versus convergence in central processing. Annual Review of Neuroscience. 2003; 26:1-30.
21. Hall JE, Hall ME. Guyton and hall textbook of medical physiology e-book. Elsevier Health Sciences. 2020.
22. Lillywhite HB. Behavioral temperature regulation in the bullfrog, rana catesbeiana. Copeia. 1970:158-168.
23. Hong SY, Lee YH, Park Het al. Stretchable active matrix temperature sensor array of polyaniline nanofibers for electronic skin. Advanced materials. 2016; 28(5):930-935.
24. Li Q, Zhang LN, Tao XM, Ding X. Review of flexible temperature sensing networks for wearable physiological monitoring. Advanced healthcare materials. 2017; 6(12):1601371.
25. Su Y, Ma C, Chen Jet al. Printable, highly sensitive flexible temperature sensors for human body temperature monitoring: A review. Nanoscale Research Letters. 2020; 15:1-34.
26. Barmpakos D, Kaltsas G. A review on humidity, temperature and strain printed sensors-current trends and future perspectives. Sensors. 2021; 21(3) : 739.
27. Li M-Z, Han S-T, Zhou Y. Recent advances in flexible field-effect transistors toward wearable sensors. Advanced Intelligent Systems. 2020; 2(11) : 2000113.
28. Li W-D, Ke K, Jia Jet al. Recent advances in multiresponsive flexible sensors towards e-skin: A delicate design for versatile sensing. Small. 2022; 18(7) : 2103734.
29. Nakamura K. Central circuitries for body temperature regulation and fever. American journal of Physiology-Regulatory, integrative and comparative Physiology. 2011; 301(5):1207-1228.
30. Jessen C. Temperature regulation in humans and other mammals. Springer Science & Business Media. 2012. 31. Stolwijk JA, Hardy J. Temperature regulation in man—a theoretical study. Pflüger's Archiv für die gesamte Physiologie des Menschen und der Tiere. 1966; 291(2):129-162.32. Lumpkin EA, Caterina MJ. Mechanisms of sensory transduction in the skin. Nature. 2007; 445(7130):858-865.33. Patapoutian A, Peier AM, Story GM, Viswanath V. Thermotrp channels and beyond: Mechanisms of temperature sensation. Nature Reviews Neuroscience. 2003; 4(7):529-539.34. Venkatachalam K, Montell C. Trp channels. Annual Review of Biochemistry. 2007; 76:387-417.35. Gordon CJ. Temperature and toxicology: An integrative, comparative, and environmental approach. CRC press. 2005. 36. Cabanac M. Temperature regulation. Annual review of physiology. 1975; 37(1):415-439.37. Robergs RA, Roberts S. Exercise physiology. Exercise, performance, andclinical applications. St. Louis: Mosby-Year Book. 1997; 840.38. Hardy JD. Physiology of temperature regulation. Physiological reviews. 1961; 41(3):521-606.39. Arens EA, Zhang H. The skin's role in human thermoregulation and comfort. 2006. 40. Hardy JD. The radiation of heat from the human body. Journal of Clinical Investigation. 1934; 13(4):593-604.41. Anderson GS. Human morphology and temperature regulation. International Journal of Biometeorology. 1999; 43:99-109.42. Gagge AP, Gonzalez RR. Mechanisms of heat exchange: Biophysics and physiology. Comprehensive physiology. 2010:45-84.43. Baker LB. Physiology of sweat gland function: The roles of sweating and sweat composition in human health. Temperature. 2019; 6(3):211-259.44. Hanna JM, Brown DE. Human heat tolerance: An anthropological perspective. Annual Review of Anthropology. 1983; 12(1):259-284.45. Terrien J, Perret M, Aujard F. Behavioral thermoregulation in mammals: A review. Frontiers in Bioscience-Landmark. 2011; 16(4):1428-1444.46. Cai J, Du M, Li Z. Flexible temperature sensors constructed with fiber materials. Advanced Materials Technologies. 2022; 7(7) : 2101182.47. Feng Y, Liu H, Zhu Wet al. Muscle-inspired mxene conductive hydrogels with anisotropy and low-temperature tolerance for wearable flexible sensors and arrays. Advanced Functional Materials. 2021; 31(46) : 2105264.48. Gu Y, Zhang T, Chen Het al. Mini review on flexible and wearable electronics for monitoring human health information. Nanoscale Research Letters. 2019; 14: 1-15.49. Nakata S, Arie T, Akita S, Takei K. Wearable, flexible, and multifunctional healthcare device with an isfet chemical sensor for simultaneous sweat ph and skin temperature monitoring. Acs Sensors. 2017; 2(3):443-448.50. Tran Quang T, Lee N-E. Flexible and stretchable physical sensor integrated platforms for wearable human-activity monitoring and personal healthcare. Advanced Materials. 2016; 28(22):4338-4372.51. Chen J, Zhu Y, Chang Xet al. Recent progress in essential functions of soft electronic skin. Advanced Functional Materials. 2021; 31(42) : 2104686.52. Khan Y, Ostfeld AE, Lochner CM, Pierre A, Arias AC. Monitoring of vital signs with flexible and wearable medical devices. Advanced Materials. 2016; 28(22):4373-4395.53. Hua Q, Sun J, Liu Het al. Skin-inspired highly stretchable and conformable matrix networks for multifunctional sensing. Nature communications. 2018; 9(1):244.54. Shih W-P, Tsao L-C, Lee C-Wet al. Flexible temperature sensor array based on a graphite-polydimethylsiloxane composite. Sensors. 2010; 10(4):3597-3610.55. Webb RC, Bonifas AP, Behnaz Aet al. Ultrathin conformal devices for precise and continuous thermal characterization of human skin. Nature Materials. 2013; 12(10):938-944.56. Choi H, Li X. Fabrication and application of micro thin film thermocouples for transient temperature measurement in nanosecond pulsed laser micromachining of nickel. Sensors and Actuators A: Physical. 2007; 136(1):118-124.57. Assumpcao D, Kumar S, Narasimhan V, Lee J, Choo H. High-performance flexible metal-on-silicon thermocouple. Scientific reports. 2018; 8(1):13725.58. Shiran Chaharsoughi M, Zhao D, Crispin X, Fabiano S, Jonsson MP. Thermodiffusion‐assisted pyroelectrics—enabling rapid and stable heat and radiation sensing. Advanced Functional Materials. 2019; 29(28):1900572.59. Root W, Bechtold T, Pham T. Textile-integrated thermocouples for temperature measurement. Materials. 2020; 13(3) : 626.60. Wu P, He Z, Yang Met al. A review on flexible thermoelectric technology: Material, device, and applications. International Journal of Thermophysics. 2021; 42(8) : 111.61. Zhang F, Zang Y, Huang D, Di C-a, Zhu D. Flexible and self-powered temperature–pressure dual-parameter sensors using microstructure-frame-supported organic thermoelectric materials. Nature communications. 2015; 6(1):8356.62. Lee J, Kim HJ, Ko YJet al. Enhanced pyroelectric conversion of thermal radiation energy: Energy harvesting and non-contact proximity sensor. Nano Energy. 2022; 97:107178.63. Albrecht A, Rivadeneyra A, Bobinger Met al. Scalable deposition of nanomaterial-based temperature sensors for transparent and pervasive electronics. Journal of Sensors. 2018; 7102069.64. Ma Z, Zhang J, Li J, Shi Y, Pan L. Frequency-enabled decouplable dual-modal flexible pressure and temperature sensor. Ieee Electron Device Letters. 2020; 41(10):1568-1571.65. Othayq MM, Giganti N, Shavezipur M. Development of capacitive temperature sensors with high sensitivity using a multiuser polycrystalline silicon process. Microelectronic Engineering. 2020; 22666. Rao L, Ding J. Capacitive sensor for testing railroad's temperature stress. Journal of Transducer Technology. 2005; 24(2):60-65.67. Othayq MM, Giganti N, Shavezipur M. Development of capacitive temperature sensors with high sensitivity using a multiuser polycrystalline silicon process. Microelectronic Engineering. 2020; 226:111287.68. Khan N, Omran H, Yao Y, et al. Flexible PVDF ferroelectric capacitive temperature sensor. 2015 IEEE 58th International Midwest Symposium on Circuits and Systems (MWSCAS). IEEE, 2015: 1-4.69. Lei Z, Wang Q, Wu P. A multifunctional skin-like sensor based on a 3d printed thermo-responsive hydrogel. Materials Horizons. 2017; 4(4):694-700.70. Fan J, Newell B, Garcia J, Voyles RM, Nawrocki RA. Effect of additive manufacturing on β‐phase poly (vinylidene fluoride)‐based capacitive temperature sensors. Advanced Engineering Materials. 2022; 24(11):2200485.71. Choi S, Park J, Hyun Wet al. Stretchable heater using ligand-exchanged silver nanowire nanocomposite for wearable articular thermotherapy. ACS nano. 2015; 9(6):6626-6633.72. Hong S, Lee H, Lee Jet al. Highly stretchable and transparent metal nanowire heater for wearable electronics applications. Advanced materials. 2015; 27(32):4744-4751.73. Yang C, Chang C, Song CYet al. Fabrication and performance evaluation of flexible heat pipes for potential thermal control of foldable electronics. Applied Thermal Engineering. 2016; 95:445-453.74. Bae SH, Shabani R, Lee JB, Baeck SJ, Cho HJ, Ahn JH. Graphene-based heat spreader for flexible electronic devices. IEEE Trans. Electron Devices. 2014; 61(12):4171-4175.75. Luo XC, Chugh R, Biller BC, Hoi YM, Chung DDL. Electronic applications of flexible graphite. Journal of Electronic Materials. 2002; 31(5):535-544.76. Im K, Cho K, Kwak K, Kim J, Kim S. Flexible transparent heaters with heating films made of indium tin oxide nanoparticles. J. Nanosci. Nanotechnol. 2013; 13(5):3519-3521.77. Hsu P-C, Liu X, Liu Cet al. Personal thermal management by metallic nanowire-coated textile. Nano letters. 2015; 15(1):365-371.78. Yang C, Song CY, Shang W, Tao P, Deng T. Flexible heat pipes with integrated bioinspired design. Progress in Natural Science. 2015; 25(1):51-57.79. Guo Y, Dun C, Xu Jet al. Ultrathin, washable, and large‐area graphene papers for personal thermal management. Small. 2017; 13(44):1702645.80. Lal S, Gautam D, Razeeb KM. Fabrication of micro-thermoelectric devices for power generation and the thermal management of photonic devices. Journal of Micromechanics and Microengineering. 2019; 29(6) : 065015.81. Ren ZQ, Kim JC, Lee J. Transient cooling and heating effects in holey silicon-based lateral thermoelectric devices for hot spot thermal management. IEEE Transactions on Components, Packaging, and Manufacturing Technology. 2021; 11(8):1214-1222.82. Song WJ, Bai FF, Chen MB, Lin SL, Feng ZP, Li YL. Thermal management of standby battery for outdoor base station based on the semiconductor thermoelectric device and phase change materials. Applied Thermal Engineering. 2018; 137:203-217.83. Wang K Y. Thermal management of a medical device using thermoelectric coolers.Twentieth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (IEEE Cat. No. 04CH37545). IEEE, 2004: 122-124.84. Solbrekken G L, Yazawa K, Bar-Cohen A. Experimental demonstration of thermal management using thermoelectric generation.The Ninth Intersociety Conference on Thermal and Thermomechanical Phenomena In Electronic Systems (IEEE Cat. No. 04CH37543). IEEE, 2004, 1: 284-290.85. Chen W-Y, Shi X-L, Zou J, Chen Z-G. Thermoelectric coolers: Progress, challenges, and opportunities. Small Methods. 2022; 6(2) : 2101235.86. Mao J, Chen G, Ren Z. Thermoelectric cooling materials. Nature Materials. 2021; 20(4):454-461.87. Pourkiaei SM, Ahmadi MH, Sadeghzadeh Met al. Thermoelectric cooler and thermoelectric generator devices: A review of present and potential applications, modeling and materials. Energy. 2019; 186: 115849.88. Zhao D, Tan G. A review of thermoelectric cooling: Materials, modeling and applications. Applied Thermal Engineering. 2014; 66(1-2):15-24.89. Li X, Mahmoud S, Al-Dadah R, Elsayed A. Thermoelectric cooling device integrated with pcm heat storage for ms patients. Energy Procedia. 2014; 61:2399-2402.90. Hong S, Gu Y, Seo JKet al. Wearable thermoelectrics for personalized thermoregulation. Science advances. 2019; 5(5):eaaw0536.91. Choi J, Dun C, Forsythe C, Gordon MP, Urban JJ. Lightweight wearable thermoelectric cooler with rationally designed flexible heatsink consisting of phase-change material/graphite/silicone elastomer. Journal of Materials Chemistry A. 2021; 9(28):15696-15703.92. Kishore RA, Nozariasbmarz A, Poudel B, Sanghadasa M, Priya S. Ultra-high performance wearable thermoelectric coolers with less materials. Nature communications. 2019; 10(1):1765.93. Bartlett MD, Kazem N, Powell-Palm MJet al. High thermal conductivity in soft elastomers with elongated liquid metal inclusions. Proceedings of the National Academy of Sciences. 2017; 114(9):2143-2148.94. Fu Y, Nabiollahi N, Wang Tet al. A complete carbon-nanotube-based on-chip cooling solution with very high heat dissipation capacity. Nanotechnology. 2012; 23(4):045304.95. Kordas K, Tóth G, Moilanen Pet al. Chip cooling with integrated carbon nanotube microfin architectures. Applied Physics Letters. 2007; 90(12):123105.96. Zhang K, Tao P, Zhang Y, Liao X, Nie S. Highly thermal conductivity of cnf/aln hybrid films for thermal management of flexible energy storage devices. Carbohydrate polymers. 2019; 213:228-235.97. Kou Y, Sun KY, Luo JPet al. An intrinsically flexible phase change film for wearable thermal managements. Energy Storage Mater. 2021; 34:508-514.98. Li W, Wang F, Cheng W, Chen X, Zhao Q. Study of using enhanced heat-transfer flexible phase change material film in thermal management of compact electronic device. Energy Conversion and Management. 2020; 210:112680.99. Liu Z, Qin S, Chen X, Chen D, Wang F. Pdms-pdms micro channels filled with phase-change material for chip cooling. Micromachines. 2018; 9(4):165.100. Shi YL, Wang CJ, Yin YF, Li YH, Xing YF, Song JZ. Functional soft composites as thermal protecting substrates for wearable electronics. Advanced Functional Materials. 2019; 29(45) : 1905470.101. Umair MM, Zhang Y, Iqbal K, Zhang SF, Tang BT. Novel strategies and supporting materials applied to shape-stabilize organic phase change materials for thermal energy storage-a review. Applied Energy. 2019; 235:846-873.102. Ferber S, Behrens AM, McHugh KJet al. Evaporative cooling hydrogel packaging for storing biologics outside of the cold chain. Advanced healthcare materials. 2018; 7(14):1800220.103. Kim J, Im S, Kim JHet al. Artificial perspiration membrane by programmed deformation of thermoresponsive hydrogels. Advanced materials. 2020; 32(6):1905901.104. Lee C, Kang S, Seo J, Lee J. Temperature-responsive on–off control over water evaporation achieved via sweat-gland-mimetic composites. ACS Applied Materials & Interfaces. 2021; 13(3):4442-4449.105. Lu Z, Strobach E, Chen N, Ferralis N, Grossman JC. Passive sub-ambient cooling from a transparent evaporation-insulation bilayer. Joule. 2020; 4(12):2693-2701.106. Wang C, Hua L, Yan H, Li B, Tu Y, Wang R. A thermal management strategy for electronic devices based on moisture sorption-desorption processes. Joule. 2020; 4(2):435-447.107. Fraivillig J. Flexible thermal management circuits bonded directly to aluminum heat sinks.PROCEEDINGS-SPIE THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING. International Society for Optical Engineering; 1999, 2003: 797-800.108. Li YH, Chen JY, Zhao S, Song JZ. Recent advances on thermal management of flexible inorganic electronics. Micromachines. 2020; 11(4) : 390.109. Xu KC, Lu YY, Yamaguchi T, Arie T, Akita S, Takei K. Highly precise multifunctional thermal management-based flexible sensing sheets. Acs Nano. 2019; 13(12):14348-14356.110. Yin YF, Cui Y, Li YH, Xing YF, Li M. Thermal management of flexible wearable electronic devices integrated with human skin considering clothing effect. Applied Thermal Engineering. 2018; 144:504-511.111. Fu Y, Hansson J, Liu Yet al. Graphene related materials for thermal management. 2D Materials. 2020; 7(1):012001.112. Balandin AA. Thermal properties of graphene and nanostructured carbon materials. Nature materials. 2011; 10(8):569-581.113. Umair MM, Zhang Y, Iqbal K, Zhang S, Tang B. Novel strategies and supporting materials applied to shape-stabilize organic phase change materials for thermal energy storage–a review. Applied Energy. 2019; 235:846-873.114. Tong JK, Huang X, Boriskina SV, Loomis J, Xu Y, Chen G. Infrared-transparent visible-opaque fabrics for wearable personal thermal management. Acs Photonics. 2015; 2(6):769-778.115. Kim Y, Lee HR, Saito T, Nishi Y. Ultra-thin and high-response transparent and flexible heater based on carbon nanotube film. Applied Physics Letters. 2017; 110(15) : 153301.116. Lim W, Khadka A, Kim BYet al. Wearable heater composites comprising traditional hanji cellulose fib ers coate d with graphene, silver nanowires, and pedot: Pss via scalable supersonic spraying. Journal of Materials Science & Technology. 2023; 164:27-36.117. Zhang JH, Xu R, Feng J, Xie Y, Zhou T. Laser direct writing of flexible heaters on polymer substrates. Industrial & Engineering Chemistry Research. 2021; 60(30):11161-11170.118. Sivarenjini TM, Panbude A, Sathiyamoorthy Set al. Design and optimization of flexible thermoelectric coolers for wearable applications. Ecs Journal of Solid State Science and Technology. 2021; 10(8) : 081006.119. Varghese T, Hollar C, Richardson Jet al. High-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals. Scientific Reports. 2016; 6120. Xu S, Li M, Dai Yet al. Realizing a 10 degrees c cooling effect in a flexible thermoelectric cooler using a vortex generator. Advanced Materials. 2022; 34(41) : 2204508.121. Choi SJ, Kwon TH, Im Het al. A polydimethylsiloxane (pdms) sponge for the selective absorption of oil from water. Acs Applied Materials & Interfaces. 2011; 3(12):4552-4556.122. Li HS, Ding Y, Ha Het al. An all-stretchable-component sodium-ion full battery. Advanced Materials. 2017; 29(23): 1700898.123. Liu W, Chen Z, Zhou GMet al. 3d porous sponge-inspired electrode for stretchable lithium-ion batteries. Advanced Materials. 2016; 28(18):3578-3583.124. Song Y, Chen HT, Su ZMet al. Highly compressible integrated supercapacitor-piezoresistance-sensor system with cnt-pdms sponge for health monitoring. Small. 2017; 13(39) : 1702091.125. Kingma BR, Frijns AJ, Schellen L, van Marken Lichtenbelt WD. Beyond the classic thermoneutral zone: Including thermal comfort. Temperature. 2014; 1(2):142-149.126. Gagge AP, Stolwijk J, Hardy J. Comfort and thermal sensations and associated physiological responses at various ambient temperatures. Environmental research. 1967; 1(1):1-20.127. Cho H, Rho H, Kim JHet al. Graphene–carbon–metal composite film for a flexible heat sink. ACS applied materials & interfaces. 2017; 9(46):40801-40809.128. Wang Q, Han X, Sommers A, Park Y, T'Joen C, Jacobi A. A review on application of carbonaceous materials and carbon matrix composites for heat exchangers and heat sinks. International journal of refrigeration. 2012; 35(1):7-26.129. Moharram KA, Abd-Elhady M, Kandil H, El-Sherif H. Enhancing the performance of photovoltaic panels by water cooling. Ain Shams Engineering Journal. 2013; 4(4):869-877.130. Huang H-S, Weng Y-C, Chang Y-W, Chen S-L, Ke M-T. Thermoelectric water-cooling device applied to electronic equipment. International Communications in Heat and Mass Transfer. 2010; 37(2):140-146.131. Lee G, Kim CS, Kim S, Kim YJ, Choi H, Cho BJ. Flexible heatsink based on a phase-change material for a wearable thermoelectric generator. Energy. 2019; 179:12-18.132. Boon-in S, Theerasilp M, Crespy D. Temperature-responsive double-network cooling hydrogels. Acs Applied Polymer Materials. 2023; 5(4):2562-2574.133. Cui S, Hu Y, Huang Z, Ma C, Yu L, Hu X. Cooling performance of bio-mimic perspiration by temperature-sensitive hydrogel. International Journal of Thermal Sciences. 2014; 79:276-282.134. Xu L, Sun DW, Tian Y, Fan TH, Zhu ZW. Nanocomposite hydrogel for daytime passive cooling enabled by combined effects of radiative and evaporative cooling. Chemical Engineering Journal. 2023; 457:12-18.135. Sato K, Kang W, Saga K, Sato K. Biology of sweat glands and their disorders. I. Normal sweat gland function. Journal of the American Academy of Dermatology. 1989; 20(4):537-563.136. Adrian R, Helmreich E, Holzer Het al. The physiology, pharmacology, and biochemistry of the eccrine sweat gland. Reviews of Physiology, Biochemistry and Pharmacology, 1977; 79:51-131.137. Wilke K, Martin A, Terstegen L, Biel S. A short history of sweat gland biology. International journal of cosmetic science. 2007; 29(3):169-179.138. Mishra AK, Wallin TJ, Pan Wet al. Autonomic perspiration in 3d-printed hydrogel actuators. Science Robotics. 2020; 5(38):eaaz3918.139. Peng Y, Zhou J, Yang Y, Lai JC, Ye Y, Cui Y. An integrated 3d hydrophilicity/hydrophobicity design for artificial sweating skin (i‐trans) mimicking human body perspiration. Advanced Materials. 2022; 34(44):2204168.140. Pu S, Su J, Li L, Wang H, Chen C, Hu X. Bioinspired sweating with temperature sensitive hydrogel to passively dissipate heat from high-end wearable electronics. Energy Conversion and Management. 2019; 180:747-756.141. Pu S, Fu J, Liao Yet al. Promoting energy efficiency via a self‐adaptive evaporative cooling hydrogel. Advanced Materials. 2020; 32(17):1907307.142. Yang P, Feng C, Liu Yet al. Thermal self‐protection of zinc‐ion batteries enabled by smart hygroscopic hydrogel electrolytes. Advanced Energy Materials. 2020; 10(48):2002898.143. Nandakumar DK, Ravi SK, Zhang YX, Guo N, Zhang C, Tan SC. A super hygroscopic hydrogel for harnessing ambient humidity for energy conservation and harvesting. Energy & Environmental Science. 2018; 11(8):2179-2187.144. Pu SR, Fu J, Liao YTet al. Promoting energy efficiency via a self-adaptive evaporative cooling hydrogel. Advanced Materials. 2020; 32(17) :1907307.145. Pu SR, Liao YT, Chen KLet al. Thermogalvanic hydrogel for synchronous evaporative cooling and low-grade heat energy harvesting. Nano Letters. 2020; 20(5):3791-3797.146. Yang PH, Feng CZ, Liu YPet al. Thermal self-protection of zinc-ion batteries enabled by smart hygroscopic hydrogel electrolytes. Advanced Energy Materials. 2020; 10(48) :2002898.147. Gomez CR. Disorders of body temperature. Handbook of clinical neurology. 2014; 120:947-957.148. Lao L, Shou D, Wu Y, Fan J. “Skin-like” fabric for personal moisture management. Science advances. 2020; 6(14):eaaz0013.149. Wang X, Huang Z, Miao D, Zhao J, Yu J, Ding B. Biomimetic fibrous murray membranes with ultrafast water transport and evaporation for smart moisture-wicking fabrics. Acs Nano. 2018; 13(2):1060-1070.150. Shou D, Fan J. An all hydrophilic fluid diode for unidirectional flow in porous systems. Advanced Functional Materials. 2018; 28(36):1800269.151. Liu Z, Wang W, Xie R, Ju X-J, Chu L-Y. Stimuli-responsive smart gating membranes. Chemical Society Reviews. 2016; 45(3):460-475.152. Liu J, Wang N, Yu L-Jet al. Bioinspired graphene membrane with temperature tunable channels for water gating and molecular separation. Nature communications. 2017; 8(1):2011.153. Kuroki H, Ohashi H, Ito T, Tamaki T, Yamaguchi T. Isolation and analysis of a grafted polymer onto a straight cylindrical pore in a thermal-responsive gating membrane and elucidation of its permeation behavior. Journal of Membrane Science. 2010; 352(1-2):22-31.154. Li Q, Zhang L-N, Tao X-M, Ding X. Review of flexible temperature sensing networks for wearable physiological monitoring. Advanced Healthcare Materials. 2017; 6(12)155. Su Y, Ma C, Chen Jet al. Printable, highly sensitive flexible temperature sensors for human body temperature monitoring: A review. Nanoscale Research Letters. 2020; 15(1) : 1-34.156. Cai JY, Du MJ, Li ZL. Flexible temperature sensors constructed with fiber materials. Advanced Materials Technologies. 2022; 7(7) : 2101182.157. Chen HR, Lou Z, Shen GZ. An integrated flexible multifunctional sensing system for simultaneous monitoring of environment signals. Science China-Materials. 2020; 63(12):2560-2569.158. Hao L, Ding JN, Yuan NYet al. Visual and flexible temperature sensor based on a pectin-xanthan gum blend film. Organic Electronics. 2018; 59:243-246.159. Lee C Y, Lee S J, Wu G W. Fabrication of micro temperature sensor on the flexible substrate. 2007 7th IEEE Conference on Nanotechnology (IEEE NANO). IEEE, 2007: 1050-1053.160. Park JS, Lee DS, Nho HW, Kim DS, Hwang TH, Lee NK. Flexible platinum temperature sensor embedded in polyimide films for curved surface temperature monitoring applications: Skin temperature of human body. Sensors and Materials. 2017; 29(9):1275-1283.161. Zhao XL, Long Y, Yang TT, Li J, Zhu HW. Simultaneous high sensitivity sensing of temperature and humidity with graphene woven fabrics. Acs Applied Materials & Interfaces. 2017; 9(35):30171-30176.162. You I, Mackanic DG, Matsuhisa Net al. Artificial multimodal receptors based on ion relaxation dynamics. Science. 2020; 370(6519):961-965.163. Madsen FB, Daugaard AE, Hvilsted S, Skov AL. The current state of silicone‐based dielectric elastomer transducers. Macromolecular rapid communications. 2016; 37(5):378-413.164. Mannsfeld SC, Tee BC, Stoltenberg RMet al. Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers. Nature materials. 2010; 9(10):859-864.165. Park S, Kim H, Vosgueritchian Met al. Stretchable energy‐harvesting tactile electronic skin capable of differentiating multiple mechanical stimuli modes. Advanced Materials. 2014; 26(43):7324-7332.166. Zhang H, Tang Q, Chan Y. Development of a versatile capacitive tactile sensor based on transparent flexible materials integrating an excellent sensitivity and a high resolution. AIP Advances. 2012; 2(2) : 022112.167. Gao Y, Yu G, Shu Tet al. 3d‐printed coaxial fibers for integrated wearable sensor skin. Advanced Materials Technologies. 2019; 4(10):1900504.168. Nie B, Li R, Cao J, Brandt JD, Pan T. Flexible transparent iontronic film for interfacial capacitive pressure sensing. Advanced Materials. 2015; 27(39):6055-6062.169. Kim H, Kim G, Kim Tet al. Transparent, flexible, conformal capacitive pressure sensors with nanoparticles. Small. 2018; 14(8):1703432.170. Tee BCK, Chortos A, Dunn RR, Schwartz G, Eason E, Bao Z. Tunable flexible pressure sensors using microstructured elastomer geometries for intuitive electronics. Advanced Functional Materials. 2014; 24(34):5427-5434.171. Ding J, Zhao W, Jin W, Di Ca, Zhu D. Advanced thermoelectric materials for flexible cooling application. Advanced Functional Materials. 2021; 31(20):2010695.172. Anno Y, Imakita Y, Takei K, Akita S, Arie T. Enhancement of graphene thermoelectric performance through defect engineering. 2D Materials. 2017; 4(2):025019.173. Xu Y, Li Z, Duan W. Thermal and thermoelectric properties of graphene. Small. 2014; 10(11):2182-2199.174. Amollo TA, Mola GT, Kirui M, Nyamori VO. Graphene for thermoelectric applications: Prospects and challenges. Critical Reviews in Solid State and Materials Sciences. 2018; 43(2):133-157.175. Russ B, Glaudell A, Urban JJ, Chabinyc ML, Segalman RA. Organic thermoelectric materials for energy harvesting and temperature control. Nature Reviews Materials. 2016; 1(10):1-14.176. Zhang Q, Sun Y, Xu W, Zhu D. Organic thermoelectric materials: Emerging green energy materials converting heat to electricity directly and efficiently. Advanced Materials. 2014; 26(40):6829-6851.