Bending kinetics of a photo-actuating nematic elastomer cantilever

Abstract

Liquid crystal elastomers (LCE) containing embedded carbon nanotubes (CNTs) contract when exposed to light, due to LC disordering induced by the ability of CNTs to absorb light and convert it into thermal energy. A cantilever made of LCE-CNTs exposed to light demonstrates dynamic bending due to inhomogeneous strain distribution caused by exponential heat generation across the cantilever width. Analysis of bending dynamics helps to extract parameters that are important for designing actuators based on these materials. In this work, we have carried out direct measurements of temperature evolution inside the cantilever and related its kinetics to the applied irradiation power.

Gas‐Pressure Molding‐Based Fabrication of Smart Actuators from Nematic Liquid‐Crystalline Elastomer

“…Thus, the actuators were thermally excited on a range from room temperature to the isotropic state, T NI ≈ 90 °C, for several cycles. The decrease in height evidenced proper actuation () in agreement with results obtained in previous works where the photo‐thermo‐mechanical properties and the actuation mechanisms of LCE‐CNT composites were already evaluated …”

“…The decrease in height evidenced proper actuation ( Figure S3) in agreement with results obtained in previous works where the photo-thermo-mechanical properties and the actuation mechanisms of LCE-CNT composites were already evaluated. [14,16,28,30] We next analyzed the photo-thermal actuation of the actuator's array by measuring their decrease in height upon illumination, as function of the optical power applied. Measurements were recorded using a confocal microscope, while irradiating the entire actuator underside by means of a LD ( Figure S5).…”

Photomobile Polymer Materials with Crosslinked Liquid‐Crystalline Structures: Molecular Design, Fabrication, and Functions

“…[89] When using CNTs in composites, it is often difficult to disperse them uniformly into matrices. Recently, promising methods have been developed to disperse CNTs in CLCP matrices such as polysiloxanes [90][91][92][93][94][95][96] and polyacrylates, [97,98] both for multi-walled [90,91,96] and single-walled [97,98] CNTs. Irradiation of a CNT/CLCP composite with visible to IR light induces a deformation of the sample.…”

Light and electrically responsive materials based on aligned carbon nanotubes

“…This photo-thermal conversion can offer ACNTs a superior opportunity in actuation applications. So many researchers select ACNTs as the photo-absorbing material to induce the thermal response of LCPs via their strong ability to capture photons and convert into local heat, thus triggering the required phase changes in the LCPs [50,51]. Camargo and co-workers prepared a LCPs/ACNTs composite film with blister-like monodomain region.…”