The mimic octopus is a truly bizarre dweller of the deep. It possesses the ability to rapidly change its skin color and texture in order to camouflage itself against its environment. In addition, it can imitate the behavior of several different animals, allowing it to “run,” slither like a snake, and even act as a jellyfish.
Now, a team of robotics engineers at Cornell University have developed an artificial skin that can stretch and change color in much the same way. As their pioneering study in the journal Science reveals, this could transform the field of robotics – particularly in the field of health care.
“Soft robotics” is a particularly new form of engineering, based around the idea that all of the components need to be flexible. These types of robots will theoretically be able to move around in restricted spaces using a variety of locomotion methods, but before they become a reality, their basic construction materials need to be developed.
This new material can crawl across the floor. Larson et al./Science
Firstly, the team wanted a material that could light up when it interacts with a strong electrical field. This phenomenon is known as “electroluminescence,” and panels of material that exhibit this trait are often referred to as light-emitting capacitors (LECs). The team at Cornell looked to find a way to develop a flexible, stretchable LEC.
This is where hydrogels come into the picture, a type of water-based, versatile material that holds its shape under a wide range of pressures and temperatures. Some hydrogels can conduct and store electricity, effectively making them electrodes.
By mixing layers of hydrogel electrodes with insulating, stretchable elastomer sheets, this team of engineers created a hyper-flexible LEC, or HLEC. When stretched, rolled or deformed – up to 480 percent of its original size without breaking – this electroluminescent material changes brightness. Far from just emitting white light, these hydrogel electrodes are designed to emit various colors of light.
At the very least, this new material could fit along a range of surfaces and display a complex range of information to the user. If several pneumatic gears are added to the base of the material, it can be stimulated to move. As a test, the authors of the study made their multicolored material crawl across the floor.
The group's latest work was supported by a grant from the Army Research Office, a 2015 award from the Air Force Office of Scientific Research, and two grants from the National Science Foundation. Larson et al./Science
Although this is only at the proof-of-concept stage, this material could prove to be a game-changer. “The field of robots is becoming a lot more mature,” Bryan Peele, a graduate student at the Organic Robotics Lab (ORL) at Cornell and one of the study’s authors, told IFLScience. “They’re moving out from factories and into places where people directly interact with them, like in healthcare.”
This flexible material could theoretically “walk” around hospitals, communicating information to patients and even assisting their hampered movement through the building. The ability to communicate using changing patterns of light may even allow the robot to convey its “mood” to someone without using text.
“A lot of communication we engage in is non-verbal,” Peele added. “And patients in a hospital would feel far more comfortable if the robot there could somehow behave in a more “natural” way – like using colors and other non-verbal expressions.”