Researchers from the University of California-Berkeley and Berkeley Lab have developed a physical sensor similar to the highly-sensitive whiskers of cats and rats. Potential applications of the sensor include equipping robots with enhanced capabilities to see and feel their environment.
"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," said lead researcher and a faculty scientist at the Berkeley Lab's Material Sciences Division Ali Javey in a press release.
The researchers developed the e-whisker by using a nanotube paste made from carbon to create an electrically conducive network which has massive flexibility and bendability properties. They also loaded a thin coat of silver nanoparticles into the carbon nanotube network. The silver nanoparticles were added to equip the matrix with sensitivity to any physical or 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 said. "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."
The researchers tested the e-whiskers sensitivity by demonstrating an accurate 3D and 2D mapping of wind flow. Similarly, e-whiskers could be also used for tactile detection for spatial mapping for objects within the immediate surroundings as well as in the development of wearable sensors which can detect pulse rate and heartbeat.
They believe that the e-whisker has high potential of being a new type of highly responsive tactile sensor networks that can monitor the changes in the environment real-time. Since it is easy to manufacture and has accurate performance, it can be used on various fields such as advanced robotics, human-machine user interfaces, and biological applications."
The study was published in the Jan. 21 issue of Proceedings of the National Academy.
