Polymer study reveals light reaction
11 Nov 2013
Researchers from the University of Pittsburgh (UOP) are investigating polymers that react and move when triggered by light, suggesting they could be used to drive robotics and morphing structures.
Microvehicles and other devices that can change shape or move with no power source other than a beam of light may be possible, according to researchers.
“I like to compare this action to that of a Venus flytrap
M. Ravi Shankar
The polymers, which essentially “snap” when triggered by light, would be capable of converting energy into mechanical work and potentially eliminating the need for traditional machine components such as switches and power sources.
Associate professor of industrial engineering at UOP M. Ravi Shankar said: “I like to compare this action to that of a Venus flytrap.
“The underlying mechanism that allows the Venus flytrap to capture prey is slow. But because its internal structure is coupled to use elastic instability, a snapping action occurs, and this delivers the power to shut the trap quickly.”
Shankar and his team focussed on the use of elastic instability to examine polymeric materials, prepared by researchers at the Air Force Research Laboratory, which demonstrated unprecedented actuation rates and output powers.
Using the light from a handheld laser, the polymers were capable of generating high amounts of power to convert the light into mechanical work without any on-board power source or wiring.
Shankar said that one of the foremost real-world applications for this polymeric technology would include the activation of a switch simply by shining a light on it.
“For example, you could develop soft machines such as stents or other biomedical devices that can be more adaptive and easily controlled.
“In a more complex mechanism, we could imagine a light-driven robotic or morphing structure, or microvehicles that would be more compact because you eliminate the need for an on-board power system. The work potential is built into the polymer itself and is triggered with light,” he added.
The study, entitled “Contactless, photoinitiated snap-through in azobenzene-functionalized polymers,” was published on October 30th in the early edition of the Proceedings of the National Academy of Sciences.
