Faculty scientist Ali Javey is leading a research team made up of researchers from Berkley Lab and the University of California, in a bid to create tactile sensors from composite films of carbon nanotubes and silver nanoparticles. These are loosely based on highly sensitive whiskers that would normally be found on cats and rats.
So far we’ve seen nanotechnology applied to e-skin or electronic eye implants. This new research, supported by DARPA, found that e-whiskers can respond to a tiny amount of pressure, as small as a single pascal, which when put in to perspective relates to the same amount of pressure exerted by a dollar bill when laid on a table surface.
“Whiskers are hair-like tactile sensors used by certain mammals and insects to monitor wind and navigate around obstacles in tight spaces,” says Javey. “Our electronic whiskers consist of high-aspect-ratio elastic fibers 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.”
The team used a carbon nanotube paste to form an electrically conductive network matrix, which was highly flexible. This was then loaded with a thin film of silver nanoparticles, which gave the matrix high sensitivity to mechanical strain.
“The strain sensitivity and electrical resistivity of our composite film is readily tuned by changing the composition ratio of the carbon nanotubes and the silver nanoparticles,” Javey explains. “The composite can then be painted or printed onto high-aspect-ratio elastic fibers to form e-whiskers that can be integrated with different user-interactive systems.”
It is hoped that this development in nanotechnology could give robots the ability to “see” and “feel” their surroundings. E-whiskers could also be used in measuring heartbeats and pulse rates.
“The ease of fabrication, light weight and excellent performance of our e-whiskers should have a wide range of applications for advanced robotics, human-machine user interfaces, and biological applications,” says Javey.
[Image via NZVA.org]