A Highly Sensitive Planer Silicon-Hair Device Reproducing the Function of Human Hair Follicle

This is the first report of a novel silicon-hair device with the function of highly sensitive hair follicle to realize peculiar sense in hairy skin of human. The target sensitivities of our device are 10μN in force and 10nN·m in moment, since they are considered as the sensitivities of human hair follicle. A fine silicon-hair with 10μm-width and 5mm-length is monolithically integrated, and 2-axis forces and 1-axis moment applied to the silicon-hair are detected independently by tri-axis sensing structure. The fabricated device was evaluated, and the minimum detectable input was 5μN in axial force, 1μN in shear force, and 3nN·m in moment. These sensitivities are advantageous to human's hair follicle, and it is very promising to apply the device to novel measurement applications. As the first application, surface tension of liquid was precisely acquired. Absolute value of surface tensions were successfully measured at small absolute error using the highly sensitive silicon-hair device.