A highly sensitive MEMS silicon‐hair device reproducing the function of hair follicle

Abstract

This paper reports a highly sensitive MEMS silicon‐hair device with novel functions of hair follicle. Human hairy skin has peculiar receptor called hair follicle. Therefore, a highly sensitive sensor reproducing the function of hair follicle is demanded in order to quantify peculiar sense in hairy skin such as wind, static electricity, and perception of the liquid surface. The developed device in this study has fine silicon‐hair with 10 µm width and 5 mm length. Moreover, it detects two‐axis force and one‐axis moment applied to silicon‐hair by piezoresistors. The MEMS silicon‐hair device has realized resolutions of 5 µN axial force, 1 µN shear force, and 3nN·m moment. Also, the device in this study precisely acquired surface tension close to the physical property of water and ethanol water solution. In addition, the MEMS silicon‐hair device was successful in detecting 0.1 µN electrostatic attraction. Resolutions of shear force and moment have been improved by 10‐fold using the resonance‐drive of silicon‐hair.