As humanoid robots become more complex, new sensors must be developed to reduce complicated circuitry and allow the androids to perform sensitive tasks, such as picking up fragile light bulbs. (Source: Wikimedia Commons)
While a patch of skin on a human’s finger can contain thousands of sensory nerves, the most advanced robots today may only have 42 sensors in their entire “hand” (1, 2). However, a new robotic hand developed by scientists at Carnegie Mellon University in collaboration with Intelligent Fiber Optic Systems Corp. and NASA contains 14 strain sensors in only four fiber optics, dramatically increasing the robots’ versatility (1, 2).
Robots in development for use in homes and workspaces typically require more sensitive components and portability in order to interact with people and adapt to unexpected situations (1, 2). There are two main problems with current sensors. The first is the need for complicated wiring, which can make the robot much larger than intended and difficult to maintain if damaged. These wires are also susceptible to damage by electromagnetic radiation, making them unreliable when used near certain electronic devices (1, 2).
Fiber optics, which are strands of pure glass that bend light in specific patterns, have the potential to solve both of these problems. Fiber optics allow light to exhibit a phenomenon known as total internal reflection, in which light bounces off the glass at specific angles and travels down the strand without losing significant amounts of energy (3). Several beams of light can travel through one optic fiber at the same time, making optic fibers effective in transmitting large quantities of information, such as multiple sensory inputs. The robot can interpret pressure on the fiber as a change in the wavelength of refracted light (1, 2).
However, further research must be done to improve optical sensor flexibility for use inside robots. Optic sensors are often difficult to manufacture and contain fluids that help detect pressure but can leak. The researchers attempted to address this issue with a new, stretchable optical sensor, but they have not yet tested it on the new hand. Nonetheless, researchers believe this new hand will provide even greater sensory capabilities for both tactile and force stimuli (1, 2).
References:
- Carnegie Mellon University. (2015, September 28). A light touch: Embedded optical sensors could make robotic hands more dexterous: Carnegie Mellon creates sensor-rich robotic hand and new stretchable sensor. ScienceDaily. Retrieved October 2, 2015 from www.sciencedaily.com/releases/2015/09/150928124356.htm
- Spice, B. (2015, September 28). A Light Touch: Embedded Optical Sensors Could Make Robotic Hands More Dexterous-CMU News – Carnegie Mellon University. Retrieved October 2, 2015.
- Freudenrich, Ph.D., C. (2001, March 6). How Fiber Optics Work. Retrieved October 5, 2015.