In the era of 4th industrial revolution, the importance of internet of things (IoT), which is the network of physical objects, has been rapidly growing. Among many core components for IoT, sensors measure physical parameters and status of objects including pressure, strain, temperature, pH, gas concentration, etc. As more sensors are deployed in numerous objects, especially in remote places, the power supply for the sensor operation is becoming a highly challenging issue. Accordingly, a number of low-power or self-powered sensors are being actively developed. In this talk, I will introduce recent development of self-powered physical and chemical sensors at our research group. In particular, the following research topics will be discussed: (1) wearable self-powered pressure sensor by integration of piezo-transmittance microporous elastomer with organic solar cell [1], (2) self-powered strain sensor based on the piezo-transmittance of a mechanical metamaterial [2], (3) self-powered H2 gas sensor based on chemo-mechanically operating palladium-polymer nanograting film [3], (4) self-powered gas sensor based on a photovoltaic cell and a colorimetric film with hierarchical micro/nanostructures [4], and (5) self-powered humidity sensor using chitosan-based plasmonic metal-hydrogel-metal filters [5]. 

[1] J. Choi, I. Park, et al., “Wearable self-powered pressure sensor by integration of piezo-transmittance microporous elastomer with organic solar cell”, Nano Energy 74, 104749 (2020)

[2] J. Gu, I. Park, et al., “Self-powered strain sensor based on the piezo-transmittance of a mechanical metamaterial”, Nano Energy 89, 106447 (2021)

[3] M.Seo, I. Park, et al., “Chemo-mechanically operating palladium-polymer nanograting film for self-powered H2 gas sensor”, ACS Nano 14, 12 (2020)

[4] K.Kang, I. Park, et al., “Self-powered gas sensor based on a photovoltaic cell and a colorimetric film with hierarchical micro/nanostructures”, ACS Applied Materials & Interfaces 12, 35 (2020)

[5] J. Jang, I. Park, et al., “Self-powered humidity sensor using chitosan-based plasmonic metal-hydrogel-metal filters”, Advanced Optical Materials 8, 1901932 (2020)