Pressure Sensitive Electronic Whiskers Developed to Help Robots Navigate

Using composite film of carbon nanotubes and silver nanoparticles, a team of international researchers has created tactile sensors that are similar to the sensitive whiskers of cats and rats. These e-whiskers can respond to changes in pressure.

In a breakthrough experiment, researchers at Berkeley Lab and the University of California (UC) developed electronic whiskers that respond to changes in pressure. These whiskers could help robots see and feel their environment.

For certain animals and insects, whiskers are important tactile sensors that help in navigating around enclosed area. But the new e-whiskers, the elastic fiber layered with nanotubes and nanoparticles are almost 10 times more sensitive to the pressure than other pressure sensors.

To develop the e-whisker, the researchers used carbon nanotube paste and formed a bendable conductive network. They then loaded a thin film of silver nanoparticles to the carbon nanotube that made the whiskers sensitive 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," lead research Ali Javey, a faculty scientist in Berkeley Lab's Materials Sciences Division and a UC Berkeley professor, says. "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."

Prior to developing e-whiskers, Javey and his colleagues have worked on developing e-skin (electronic skin) for robotic limbs.

The nanotubes gave the whiskers a great flexibility and also rendered extreme sensitivity. This e-whisker has many applications.

According to Guardianlv, the e-whiskers could be use to sense the pulse or heartbeat and also create 2D and 3D models of wind flow; it can be used to get precise wind flow readings. Further, by altering the composition ratio of the both the silver nanoparticles and carbon nanotubes, the sensitivity of the film used for developing the whiskers can be changed.

"Our e-whiskers represent a new type of highly responsive tactile sensor networks for real time monitoring of environmental effects," Javey says. "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 findings have been published in the Proceedings of the National Academy of Sciences.