Optical sensors may be especially suitable to be used in robotic limbs, according to scientists at Carnegie Mellon University who have created a three-fingered soft robotic limb with numerous integrated fiber optic sensors. They have also developed a new kind of pliable optical sensor.

“If you want robots to work autonomously and to react safely to unexpected forces in everyday environments, you need robotic hands that have more sensors than is typical today,” said Yong-Lae Park, assistant professor of robotics. “Human skin contains thousands of tactile sensory units only in the fingertip and a spider has hundreds of mechanoreceptors on each leg, but even a state-of-the-art humanoid such as NASA’s Robonaut has only 42 sensors in its hand and wrist.”

Adding conventional pressure or force sensors is problematic because wiring can be complicated, prone to breaking and susceptible to interference from electric motors and other electromagnetic devices. But a single optical fiber can contain several sensors; all of the sensors in each of the fingers of the CMU hand are connected with four fibers, although, theoretically, a single fiber could do the job, Park said. And the optical sensors are impervious to electromagnetic interference.

Original source: http://www.cmu.edu/