Park, Tae Hyun Park, Seongjin Yu, Seunggun Park, Sangun Lee, Junseok Kim, Sunho Jung, Youngmee Yi, Hyunjung 2024-01-19T14:30:34Z 2024-01-19T14:30:34Z 2021-10-21 2021-07 2192-2640 https://pubs.kist.re.kr/handle/201004/116798 The development of electrically responsive sensors that interact directly with human skin and at the same time produce a visual indication of the temperature is in great demand. Here, we report a highly sensitive electronic skin (E-skin) sensor that measures and visualizes skin temperature simultaneously using a biocompatible hydrogel displaying thermoresponsive transparency and resistivity resulting from a temperature dependence of the strength of the hydrogen bonding between its components. This thermoresponsive hydrogel (TRH) showed a temperature dependence of not only the proton conductivity but also of its transmittance of light through a change in polymer conformation. We were able to use our TRH temperature sensor (TRH-TS) to measure temperature in a wide range of temperatures based on a change in its intrinsic resistivity (-0.0289 degrees C-1) and to visualize the temperature due to its thermoresponsive transmittance (from 7% to 96%). The TRH-TS exhibited high reliability upon multiple cycles of heating and cooling. The on-skin TRH-TS patch is also shown to successfully produce changes in its impedance and optical transparency as a result of changes in skin temperature during cardiovascular exercise. This work has shown that our biocompatible TRH-TS is potentially suitable as wearable E-skin for various emerging flexible healthcare monitoring applications. English WILEY NETWORK HYDROGELS STRAIN Highly Sensitive On-Skin Temperature Sensors Based on Biocompatible Hydrogels with Thermoresponsive Transparency and Resistivity Article 10.1002/adhm.202100469 1 ADVANCED HEALTHCARE MATERIALS, v.10, no.14 ADVANCED HEALTHCARE MATERIALS 10 14 scie scopus 000653209800001 2-s2.0-85106313826 Engineering, Biomedical Nanoscience & Nanotechnology Materials Science, Biomaterials Engineering Science & Technology - Other Topics Materials Science Article NETWORK HYDROGELS STRAIN electronic skin hydrogels temperature sensors upper critical solution temperature (UCST) visualization sensors wearable sensors