American Chemical Society
am3c00916_si_002.mp4 (1.3 MB)

Flexible Wearable Capacitive Sensors Based on Ionic Gel with Full-Pressure Ranges

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posted on 2023-03-17, 14:04 authored by Mengqin Zhang, Mingxin Gu, Li Shao, Guanyin Cheng, Hailin Gao, Bihao Sun, Sen Li, Tian Tang, Nan Li, Yuanbang Yi, Dacheng Wei, Ce Yang, Dapeng Wei
Flexible positive pressure sensors have been studied extensively and have been used in a lot of scenarios. However, negative pressure detection is also in demand in some scenarios, such as fluid mechanics analysis, air pressure sensing, and so on. Flexible wearable sensors that can detect both positive and negative pressures will greatly broaden the application field. In this paper, we report a flexible highly sensitive ionic gel (IG) pressure sensor, which is simple and of low cost to prepare and can reliably detect a large pressure range from −98 to 100 kPa under an atmospheric pressure of about 982 hPa. The IG dielectric layer is composed of polyvinyl alcohol and phosphoric acid with a random microstructure of sandpaper inversion. The sensor exhibits flexibility, cycling stability, and high sensitivity under both negative and positive pressures (S = 84.45 nF/kPa for the negative pressure section, S = 25.61 nF/kPa for the positive pressure section). These sensors could be worn on the body not only to test breathing and pulse but also to measure air pressure for estimating the altitude, showing that the flexible full-pressure sensors have a wider application range in wearable electronics.