Photomotility of polymers.
Light is distinguished as a contactless energy source for microscale devices as it can be directed from remote distances, rapidly turned on or off, spatially modulated across length scales, polarized, or varied in intensity. Motivated in part by these nascent properties of light, transducing photonic stimuli into macroscopic deformation of materials systems has been examined in the last half-century. Here we report photoinduced motion (photomotility) in monolithic polymer films prepared from azobenzene-functionalized liquid crystalline polymer networks (azo-LCNs). Leveraging the twisted-nematic orientation, irradiation with broad spectrum ultraviolet-visible light (320-500 nm) transforms the films from flat sheets to spiral ribbons, which subsequently translate large distances with continuous irradiation on an arbitrary surface. The motion results from a complex interplay of photochemistry and mechanics. We demonstrate directional control, as well as climbing.
Air Force Research Laboratory, Materials &Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, USA.|Azimuth Corporation, Dayton, Ohio 45432, USA.|Inha University, Department of Polymer Science and Engineering, Incheon 22212, South Korea.
Jeong Jae
JJ
Wie
University of Pittsburgh, Department of Industrial Engineering, Pittsburgh, Pennsylvania 15261, USA.
M Ravi
MR
Shankar
Air Force Research Laboratory, Materials &Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, USA.
Timothy J
TJ
White