E-Whiskers Help Robots ‘Feel’ Their Surroundings, ‘Most Sensitive’ Tactile Sensors Ever Developed

Robots may soon have the ability to “feel” thanks to a new invention made by researchers at Berkeley Lab and the University of California, Berkeley.

Using composite films of carbon nanotubes and silver nanoparticles, researchers have created e-whiskers – tactile sensors that resemble those of cats and rats. The whiskers respond to even the slightest pressure, giving robots a new way to “see” and “feel” their surroundings.

“Whiskers are hair-like tactile sensors used by certain mammals and insects to monitor wind and navigate around obstacles in tight spaces," Ali Javey, an associate professor of electrical engineering and computer sciences at the University of California, Berkeley, said in a statement. "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 findings, published in the Proceedings of the National Academy of Sciences, described how the team replaced hair follicles with nanomaterials and nerve endings with electronic instrumentation to create the highly sensitive tactile sensors.

"It's the most sensitive-pressure sensor yet developed," Dr. Kuniharu Takei, of Osaka Prefecture University in Japan, one of the study’s authors, told the Australian Broadcast Corporation.

In the latest findings, Javey and his team used the e-whiskers to create accurate 2D and 3D maps of wind flow. But the team anticipates the invention will be used for spatial mapping of nearby objects, and could also lead to wearable sensors for measuring heartbeat and pulse rate.

"Our e-whiskers represent a new type of highly responsive tactile sensor network for real-time monitoring of environmental effects," Javey said. "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." What's more, the whiskers are inexpensive to produce.

Javey says they can be incorporated into more-complex systems, and even customized. By changing the ratio of the carbon nanotubes and silver nanoparticles, the whiskers’ sensitivity could be tailored to perform specific tasks.

"It's particularly impressive that the sensitivities can be tuned," Mitra Hartmann, associate professor of biomedical and mechanical engineering at Northwestern University, told Popular Mechanics. "These whiskers could be used to imitate the fish 'lateral line' system to increase stability and maneuverability of underwater vehicles."

Takei predicts the invention could be used to develop artificial skin.

"The applications are mainly for robotic skin, prosthetic skin, and some other human interface devices," he said.