Search Here

A team of scientists have created a tactile sensors made from composite films of carbon nanotubes and silver nano-particles that can feel as small as a single Pascal of pressure. A single Pascal is equivalent to the pressure that is exerted on a table surface by a dollar bill. 

The findings can be utilized in robotics that could enable robots in "seeing" and "feeling" the 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 Ali Javey, a faculty scientist in Berkeley Lab's Materials Sciences Division and a UC Berkeley professor of electrical engineering and computer science, according to RedOrbit.

"Our electronic whiskers consist of high-aspect-ratio elastic fibers coated with conductive composite films of nanotubes and nano-particles. In tests, these whiskers were 10 times more sensitive to pressure than all previously reported capacitive or resistive pressure sensors."

Researchers used a carbon nanotube paste for forming an electrically conductive network matrix, which was loaded with a thin film of silver nano-particles. 

"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 added. "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."

Researchers said using elastic fibers with small spring constant in the form of structural component of the whiskers provided large deflection. It also enabled the system to detect even the smallest applied pressure. 

"Our e-whiskers represent a new type of highly responsive tactile sensor networks for real time monitoring of environmental effects," Javey said, according to RedOrbit. "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."

The study is published in the Proceedings of the National Academy of Sciences.