Mould-Free Skin-Inspired Robust and Sensitive Flexible Pressure Sensors With Hierarchical Microstructures

• Published in: IEEE electron device letters 2021-10, Vol.42 (10), p.1536-1539
• Main Authors: Ma, Chao, Xu, Dong, Liu, Wenfeng, Dong, Tianyu, Li, Sheng-Tao
• Format: Article
• Language: English
• Subjects: Dynamic range; electronic-skin; hierarchical microstructures; Hysteresis; Microstructure; Molds; mould-free; Pressure sensors; Robot sensing systems; Sensitivity; Sensors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2021.3109035

Flexible microscopic pressure sensors are important to the emerging fields of intelligent robots and advanced healthcare. However, common microstructured pressure sensors often require sophisticated mould and/or material preparation, and yield limited pressure sensing performances. In this letter, we report a facile approach to design a scalable and stretchable mould-free sensitive layer with a unique hierarchical microstructure. Inspired by natural skin, a sensitive layer with interdigitated electrodes is utilized to constructed into resistive pressure sensors, which are able to robustly detect the pressure variations with high sensitivity in a wide dynamic range (about 33\,\,kPa^{-1} below 5 kPa, more than 0.6\,\,kPa^{-1} under 108 kPa), also deliver low hysteresis (within 8%), rapid response (less than 48 ms), and ultralow operation voltage ( 10~{\mu }V ). We illustrate that such self-patterned high-performance pressure sensors can be applied to convert the pressure stimulus into spike-like signals in both low- and medium-pressure regimes, and are being able to clearly reveal the details of human pulse wave.