Whiskers are biological sensors—nature's adorable answer to overcoming poor eyesight and allowing nighttime navigation. Capable of detecting even the slightest wisps of air, whiskers help cats hunt in utter darkness and allow insects to negotiate tight spaces.
Given recent advances in biomimicry, it was only a matter of time before scientists granted machines a similar sensory power by outfitting robots with artificial whiskers. Ali Javey, an associate professor of electrical engineering and computer sciences at the University of California, Berkeley, has done it. Javey's robo-whiskers made their debut in a study in the journal PNAS. [Editor's Note: Link to study will go live in the afternoon of Tuesday, January 21.]
E-whiskers use wispy nanomaterials in place of hair follicles, and swap out nerve endings for electronic instrumentation. But Javey maintains that his creation is fundamentally like its biological analogue. "The sensing mechanism is quite different, but the functionality is very similar," he says.
To craft the perfect e-whisker, Javey and his team sought out nanomaterials that were both lightweight and highly sensitive to strain. Carbon nanotubes lent the whiskers their flexibility, while silver nanoparticles increased their sensitivity. By tinkering with the proportion of carbon to silver, Javey's team demonstrated that the e-whiskers could be customized 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, tell PopMech via email.
From underwater drones to smarter land bots, Hartmann suspects that artificial whiskers could have a wide variety of robotic applications. "These whiskers could be used to imitate the fish 'lateral line' system to increase stability and maneuverability of underwater vehicles," she wrote. "Or, they could be used as direct tactile sensors, just as rodents use their whiskers to sense features of the environment."
Artificial whiskers are simple and inexpensive to produce, Javey says, so the next step will be to integrate these sensors into more complex systems. Researchers may ultimately incorporate e-whisker technology into lightweight, wearable sensors, capable of detecting joint movements and even pulse rates. "Electronic whiskers could provide a robotic arm with yet another degree of sensing ability," Javey says.