Electrochromic devices have seen widespread adoption in the automotive and aerospace industries. These elements are increasingly considered for applications in the built environment, as smart windows. Functionally, application of an electric field to either an inorganic, metallic, or polymeric material results in rapid control of dynamic optical properties.<br/>Here we report a distinctive approach to realizing electrochromism in polymeric materials. We prepared liquid crystalline elastomers (LCEs) that retain the cholesteric phase (CLCEs). Enabled by the retention of the periodic structure of the cholesteric phase, the CLCEs naturally exhibit a selective reflection. Here, we introduce the integration of flexible, optically transparent conductive electrodes so as to subject the CLCEs to actuation via Maxwell stresses. The electromechanical mechanism is analogous to dielectric elastomer actuators.<br/>Upon application of a DC electric field, a Maxwell stress is imposed on the active layer and results in reversible and controlled reconfiguration of its inherent photonic properties. We demonstrate how pre-strain results in depolarization of this reflection band, retention of higher-order Bragg reflections, and will discuss materials enhancement to improve the electrochromic tunability of the device.

Tuning the selective reflection of fully solid, polymeric elements with electric field

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.