Robots with Whiskers; Berkeley Scientists Create Highly Sensitive Tactile Sensors

Scientists at Berkeley Lab and the University of California (UC) Berkeley have now created whiskers using carbon nanotubes and silver nanoparticles.

These e-whiskers, researchers say, act just like whiskers in rats and cats and are designed to help robots get a better idea of their surroundings.

Whiskers are tiny, modified hair called vibrissae and are an extension of touch organs. Many mammals have whiskers at some or the other stage of their lives, except humans. Although, we still have remnants of the muscles associated with these vibrissae.

The new e-whiskers are designed to mimic the function of hair found on cats and rats. According to researchers, these sensory organs are highly sensitive to changes in pressure and can let robots "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," said the leader of this research Ali Javey, a faculty scientist in Berkeley Lab's Materials Sciences Division.

"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," Javey said in a news release.

How did they make these sensors?

Researchers used carbon nanotube paste to create a bendable network matrix that could conduct electricity. They then added a thin film of silver nanoparticles, which increased the matrix's sensitivity to mechanical strain, according to a news release.

The team then tested the sensor by using it to map wind flow. According to researchers, e-whiskers can be used in many fields.

"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 was supported by the Defense Advanced Research Projects Agency and is published in the journal Proceedings of the National Academy of Sciences.