Carnegie Mellon Creates Sensor-rich Robotic Hand and New
Stretchable Sensor
(September 28, 2015) Optical
sensors may be uniquely suited for use in robotic hands, according to Carnegie
Mellon University researchers who have developed a three-fingered soft robotic
hand with multiple embedded fiber optic sensors. They also have created a new
type of stretchable optical sensor.
By using fiber optics, the researchers were able to embed 14
strain sensors into each of the fingers in the robotic hand, giving it the
ability to determine where its fingertips are in contact and to detect forces
of less than a tenth of a newton. The new stretchable optical sensing material,
not incorporated in this version of the hand, potentially could be used in a
soft robotic skin to provide even more feedback.
“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.”
The new
stretchable optical sensor coud be used in
a soft rotobic
skin to detect contact and measure force.
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.
The Carnegie Mellon researchers will discuss the robotic
hand, developed together with researchers at Intelligent Fiber Optic Systems
Corp., with support from NASA, Sept. 29 at the IEEE International Conference on
Intelligent Robots and Systems, IROS 2015, in Hamburg, Germany. A report on the
highly stretchable optical sensors will be presented Oct. 1 at the same
conference.