Controlling devices with a beam of light
Could make possible light-activated microrobotic and biomedical devices --- batteries not required
November 14, 2013
“Learning from ideas observed in the natural world, we created mechanical designs that generate ultrafast actuation when triggered with light,” M. Ravi Shankar, lead author of the study and associate professor of industrial engineering in the University’s Swanson School of Engineering, told KurzweilAI. “This allowed us to generate actuation at millisecond time-scales and power densities approaching kilowatts per cubic meter.”
“I like to compare this action to that of a Venus flytrap,” he said. “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. A similar mechanism acts in the beak of the Hummingbird to help snap-up insects
“You could activate a switch simply by shining light on it,” Shankar says. “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.”
The research could “drive microfluidics and biomedical devices, power microrobots and actuators without using onboard power systems or wiring or even create morphing structures and surfaces that transform when suitably irradiated with light,” Shankar explained to KurzweilAI. However, “we are still at the fundamental research level and the opportunities for new system designs are being examined.”
Abstract of PNAS paper
Photomechanical effects in polymeric materials and composites
transduce light into mechanical work. The ability to control the
intensity, polarization, placement, and duration of light irradiation is
a distinctive and potentially useful tool to tailor the location,
magnitude, and directionality of photogenerated mechanical work.
Unfortunately, the work generated from photoresponsive materials is
often slow and yields very small power densities, which diminish their
potential use in applications. Here, we investigate photoinitiated
snap-through in bistable arches formed from samples composed of
azobenzene-functionalized polymers (both amorphous polyimides and liquid
crystal polymer networks) and report orders-of-magnitude enhancement in
actuation rates (approaching 102 mm/s) and powers (as much as 1 kW/m3).
The contactless, ultra-fast actuation is observed at irradiation
intensities <<100 a="" actuation="" actuators="" adaptive="" an="" and="" as="" at="" be="" bidirectional="" bistability="" can="" cm2.="" contactless="" demonstrated.="" design="" developed="" devices="" distances="" div="" due="" elements.="" elucidate="" focusing="" for="" from="" generators="" geometry="" impulse="" in="" is="" isolating="" laboratory-on-chip="" large="" light="" materials="" mechanical="" mechanics="" meso-="" micro-="" microfluidic="" microvehicles="" millimeter="" mixers="" model="" mw="" of="" on="" optical="" otherwise="" passive="" photomechanical="" potentially="" properties="" reversible="" role="" sample="" scales="" snap-through="" specifically="" standoff="" strain.="" structure="" switches="" symmetry="" that="" the="" to="" tool="" trigger="" triggered="" ultrafast="" underlying="" use="" using="" valves="" versatile="" well="">
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(¯`*• Global Source and/or more resources at http://goo.gl/zvSV7 │ www.Future-Observatory.blogspot.com and on LinkeIn Group's "Becoming Aware of the Futures" at http://goo.gl/8qKBbK │ @SciCzar │ Point of Contact: www.linkedin.com/in/AndresAgostini100>