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.

Preparation of liquid crystalline polymer networks containing a cinnamyl group in the main chain with tunable thermal actuation behavior

“…A monodomain liquid crystal network (LCN) actuator was easily prepared by uniaxial stretching in the LC phase, after which the photochemical reaction of the cinnamyl group was used to crosslink and fix the liquid crystal orientation structure. Finally, an LCN actuator with complex and programmable shape changes was realized by spatially configuring or patterning the monodomain through photocrosslinking . Then, the influence of the initial strain on the actuation behavior was investigated, which mechanically suppressed smectic ordering in the used LCP and provided a broad nematic‐isotropic phase transition that endowed the LCN with a readily available multitemperature memory actuation effect .…”

“…Finally, an LCN actuator with complex and programmable shape changes was realized by spatially configuring or patterning the monodomain through photocrosslinking. 39,40 Then, the influence of the initial strain on the actuation behavior was investigated, which mechanically suppressed smectic ordering in the used LCP and provided a broad nematic-isotropic phase transition that endowed the LCN with a readily available multitemperature memory actuation effect. 41 Generally, the thermal response behavior of LCEs or LCNs, such as the actuation temperature, response speed and reversible actuation degree (L/L iso ), mainly depends on the order-disorder phase transition and degree of crosslinking.…”

(Photo)Thermal Stimulation of Functional Dithiolene Complexes in Soft Matter

“…Along these lines, the ([Ni(R 2 timdt) 2 ]) complex functionalized by 2‐butyloctyl carbon chains (8(4) complex) was physically entrapped into an elastomer constructed from biphenyl unit and photopolymerizable cinnamyl moieties for cross‐linking (Figure a and b) . Absorption of the complex is slightly blue‐shifted to 974 nm in the photopolymerized film (Figure b).…”

“…(d) Reversible curling for the asymmetric film between the nematic phase and the isotropic phase. Reproduced from ref …”

“…(b) Photographs showing laser‐driven transportation of a carbon bar pushed by the bump along the actuator strip. Reproduced from ref …”