Intelligently actuating liquid crystal elastomer‐carbon nanotube composites

H Kim, JA Lee, CP Ambulo, HB Lee… - Advanced Functional …, 2019 - Wiley Online Library
H Kim, JA Lee, CP Ambulo, HB Lee, SH Kim, VV Naik, CS Haines, AE Aliev
Advanced Functional Materials, 2019Wiley Online Library
Strategies for obtaining materials that respond to external stimuli by changing shape are of
intense interest for the replacement of traditional actuators. Here, a strategy that enables
programmable, multiresponsive actuators that use either visible light or electric current to
drive shape change in composites comprising carbon nanotubes (CNTs) in liquid crystal
elastomers (LCEs) is presented. In the nanocomposites, the CNTs function not only in the
traditional roles of mechanical reinforcement and enhancers of thermal and electrical …
Abstract
Strategies for obtaining materials that respond to external stimuli by changing shape are of intense interest for the replacement of traditional actuators. Here, a strategy that enables programmable, multiresponsive actuators that use either visible light or electric current to drive shape change in composites comprising carbon nanotubes (CNTs) in liquid crystal elastomers (LCEs) is presented. In the nanocomposites, the CNTs function not only in the traditional roles of mechanical reinforcement and enhancers of thermal and electrical conductivity but also serve as an alignment layer for the LCEs. By controlling the orientation, location, and quantity of layers of CNTs in LCE/CNT composites, programmed, patterned actuators are built that respond to visible light or electrical current. Photothermal LCE/CNT film actuators undergo fast shape change, within 1.2 s using 280 mW cm−2 light input, and complex, programmed localized deformations. Furthermore, twisting LCE/CNT composite films into a fiber increases uniaxial muscle stroke and work capacity for electrothermal actuation, thereby enabling about 12% actuation strain and 100 kJ m−3 of work capacity in response to an applied DC voltage of 15.1 V cm−1.
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