A Multifunctional Dye‐doped Liquid Crystal Polymer Actuator: Light‐Guided Transportation, Turning in Locomotion, and Autonomous Motion

Abstract

A strip of a liquid crystal elastomer doped with a near‐infrared dye with one side crosslinked monodomain and the other crosslinked polydomain along the thickness behaves like a multifunctional photoactuator without the need for a support. A flat strip with two ends fixed on substrate surface forms a moving bump under laser scanning, which can be used as light‐fueled conveyor to transport an object. Cutting off and laser scanning the bump with two free ends makes a soft and flexible millimeter‐scale crawler that can not only move straight and climb an inclined surface, but also undergo light‐guided turning to right or left as a result of combined out‐of‐plane and in‐plane actuation. Based on the self‐shadowing mechanism, with one end of the strip fixed on substrate surface, it can execute a variety of autonomous arm‐like movements under constant laser illumination, such as bending–unbending and twisting, depending on the laser incident angles with respect to the strip actuator.

Bioinspired light-driven soft robots based on liquid crystal polymers

“…Light-driven oscillation of liquid crystal cantilevers upon exposure to constant high intensity light has been demonstrated. 27,[39][40][41][42][43][44] The mechanism for such oscillations commonly relies on the fast photothermal deformation of the LCP to move the material into and out of the light beam, with a feedback loop sustaining the motion. Such work has pioneered the development of devices displaying continual locomotion 18,24 or rotational, mill-like motion, 45 Fig.…”

“…(A: Reproduced with permission,22 Copyright 2016, Wiley VCH. B: Reproduced with permission,27 Copyright 2018, Wiley VCH. C: Reproduced with permission,23 Copyright 2009, Royal society of Chemistry.…”

Shape-Memory Polymeric Artificial Muscles: Mechanisms, Applications and Challenges

“…This makes the spiropyran a promising candidate for the further design of light-responsive polymeric materials [ 109 ]. Similarly, Zhao and his co-workers [ 110 ] reported a dye-doped liquid crystal polymer containing a metal-bis-dithiolene complex as a molecular photothermal agent. In their article, they observed that with two ends of a strip fixed, a NIR laser could generate a wave that pushed a rod forwards or backwards.…”

“… ( a ) Spiropyran-based molecular switch and the UV-vis absorption spectra in response to different stimuli (Reprinted (adapted) from ). ( b ) Chemical structure of the liquid crystal elastomer containing 2-butyloctyl carbon chains and autonomous arm-like motions of the strip actuator under constant illumination of a laser (Reprinted (adapted) with permission [ 110 ]. Copyright (2012) John Wiley and Sons).…”

Robust Dynamics of Synthetic Molecular Systems as A Consequence of Broken Symmetry

“…[23] (a) (b) (c) Applying stimuli-responsive materials, oscillatory motions and directional motions have also been reported. [27][28][29][30][31][32][33][34][35][36][37][38][39] Stimuli-responsive materials generally terminate their motion when the systems achieve equilibrium. The oscillations in those studies were motivated by the coupling of the directionality of external energy-supply and the time-delayed transition of materials.…”