Actuators based on liquid crystalline elastomer materials

Abstract

Liquid crystalline elastomers (LCEs) exhibit a number of remarkable physical effects, including the unique, high-stroke reversible mechanical actuation when triggered by external stimuli. This article reviews some recent exciting developments in the field of LCEs materials with an emphasis on their utilization in actuator applications. Such applications include artificial muscles, industrial manufacturing, health and microelectromechanical systems (MEMS). With suitable synthetic and preparation pathways and well-controlled actuation stimuli, such as heat, light, electric and magnetic field, excellent physical properties of LCE materials can be realized. By comparing the actuating properties of different systems, general relationships between the structure and the property of LCEs are discussed. How these materials can be turned into usable devices using interdisciplinary techniques is also described.

Side Chain Liquid Crystalline Polymers: Advances and Applications

“…These LCEs have numerous potential applications, such as: soft actuators, artificial muscles and nonlinear optical devices (Urayama 2007;Jiang et al 2013). The coupling of the mesogen alignment with elastomeric networks also yields many academically interesting issues, such as: nonsymmetric elasticity, unusual phase transition and significantly, nonlinear mechanical responses.…”

Light and electrically responsive materials based on aligned carbon nanotubes

“…Once the LCPs is heated above or cooled down below its nematicisotropic transition temperature, the alignment of mesogens is changed, and the spontaneous uniaxial contraction/restoration of the LCPs along the axis results in spontaneous elongation or contraction of the whole network along the nematic direction. After the nematic-isotropic phase transition, the LCPs revert to their original state and make the polymer material contract along the director axis [49]. In many cases, functionalized CNTs are also used as nanoscale heaters and thermal conductors to induce the thermal phase transitions of LCPs.…”

Morphing in nature and beyond: a review of natural and synthetic shape-changing materials and mechanisms

“…ABA triblock copolymers allow the construction of alternative structures, such as dilute gels [54]. Options for components and synthetic routes are discussed by Ohm [51], and other useful reviews may be found in Jiang et al [55], Chambers et al [56], and White et al [37]. Existing issues and open questions are highlighted by Urayama [57].…”