Photomotility of polymers

Abstract

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.

Simple Synthesis of Elastomeric Photomechanical Switches That Self‐Heal

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Shape‐Shifting Azo Dye Polymers: Towards Sunlight‐Driven Molecular Devices

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Kirigami‐Based Light‐Induced Shape‐Morphing and Locomotion

“…The interplay between intrinsic materials properties and the external stimuli can lead to intriguing phenomena in soft materials, such as self‐oscillation, wave‐like self‐propelling and various forms of self‐sustained motion . Those phenomena are initiated by an in‐built feedback mechanism connecting the material response, stimulus fields, and the structural geometry .…”