The effects of network architecture on the photomechanical performance of azo-acrylate liquid crystal elastomers

TL;DR

This paper investigates how different network architectures influence the photomechanical behavior of azo-acrylate liquid crystal elastomers, focusing on the mechanisms driving their response to light.

Contribution

It provides new insights into the relationship between network structure and photomechanical performance, highlighting the roles of order parameter change and direct contractile stress.

Findings

Order parameter change significantly affects stress generation.

Direct contractile stress contributes to overall response.

Network architecture modulates the balance of these mechanisms.

Abstract

Azo-containing liquid crystal elatomers are photomechanical materials which can be actuated by illumination. The photomechanical response is a result of the photoisomerization of the azo moiety, which produces bulk stresses in the material. These stresses arise via two distinct and competing mechanisms: order parameter change induced stress and direct contractile stress. We describe thermomechanical and photomechanical experiments aimed at assessing the relative contributions of these. we discuss our results and summarize our findings.