Lightweight Whiskers for Contact, Pre-Contact, and Fluid Velocity Sensing

This letter reports the design, fabrication, and testing of lightweight whisker sensors intended for use on robotic platforms, especially drones, featuring multiple whisker fibers in an array. The whiskers transmit forces along the vibrissae fibers to a load plate bonded to embedded MEMS barometers potted in polyurethane rubber, which act as force sensors. This construction allows for directional sensing of forces with arrays of fibers weighing less than half a gram per whisker. Forces as low as 3.33 <inline-formula><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula>N can be measured, and the whiskers are capable of sensing fluid stream velocities up to 7.5 m<inline-formula><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula>s<inline-formula><tex-math notation="LaTeX">$^{-1}$</tex-math></inline-formula>. The whiskers are sufficiently sensitive so as to be able to detect the pressure wave of an approaching hand moving at 0.53 m<inline-formula><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula>s<inline-formula><tex-math notation="LaTeX">$^{-1}$</tex-math></inline-formula> from 20 mm away.