Strengthening Actuation of Liquid Crystal Elastomers via Double-Network Construction with Meshed Fabrics.

Abstract

Liquid crystal elastomers (LCEs) have attracted wide interest due to their characteristic large strain in actuation. However, their high transition temperatures to the isotropic phase (<i>T</i>_I) and poor mechanical strength still limit their applications. Here, an LCE network was modified with poly(ethylene glycol) soft segments to lower its <i>T</i>_I, which was adjusted close to body temperature. Additionally, a mesh-structured power-net fabric in a prestretched state was introduced into the LCE matrix to reinforce the soft actuators via construction of a double network. The obtained fabric-reinforced LCE exhibited a high Young's modulus (12.3 MPa, 3 times that of LCE) and an actuation strain of 15%. During one actuation cycle, it experienced a retractive stress of 1.21 MPa, accompanied by a maximum work density of 138 kJ/m³. Both the mechanical and actuation properties of the LCE have been improved. This new strategy of combination brought the LCE actuators closer to practical applications.