Cats' whiskers inspire nanotube sensors

These so-called e-whiskers, developed by researchers at Berkeley Lab and the University of California (UC) Berkeley, are said to respond to pressure as slight as a single Pascal. Potential applications include giving robots new abilities to manoeuvre within their surrounding environment.

‘Whiskers are hair-like tactile sensors used by certain mammals and insects to monitor wind and navigate around obstacles in tight spaces,’ said the research leader Ali Javey, a faculty scientist in Berkeley Lab’s Materials Sciences Division and a UC Berkeley professor of electrical engineering and computer science. ‘Our electronic whiskers consist of high-aspect-ratio elastic fibres coated with conductive composite films of nanotubes and nanoparticles. In tests, these whiskers were 10 times more sensitive to pressure than all previously reported capacitive or resistive pressure sensors.’

For this project, Javey and his research group used a carbon nanotube paste to form a bendable electrically conductive network matrix. They then loaded the carbon nanotube matrix with a thin film of silver nanoparticles that endowed the matrix with high sensitivity to mechanical strain.