Infrared Electrochromic Conducting Polymers for Wearable and Nanophotonic Applications

Abstract

Conducting polymers are used in a wide range of applications since their discovery. They are particularly attractive to tunable devices that can effectively operationalize the large optical contrast by applying electrical voltage and signals. Given the increasing need in energy efficiency and performance, personal thermoregulation and tunable nanophotonic devices are ideal platforms to utilize the electrochromic properties of conducting polymers by changing their optical dispersion of through electrochemical reactions. However, studying electrochromic conducting polymers and incorporating them into devices can be challenging due to their dynamic change in response to external stimulation. Their performance and processability can be further complicated by the variation in composition, structures, and charge transport properties. This leads to the limitation to tunability, characterization, fabrication, and integration. Many new opportunities remain unexplored, especially the materials design and incorporation of conducting polymers in infrared or thermal applications. This dissertation explores the potential of using infrared electrochromic conducting polymers to incorporate dynamic functionality in wearable and nanophotonic applications. The research begins with a wearable variable emittance device (WeaVE) that stabilizes human body radiative heat loss through a kirigami-enabled soft electrochemical cell with minimal energy input. The dissertation also leverages the understanding in optical properties, synthesis, and solution processability to demonstrate a tunable thermal emitter using conducting polymers. The proposed method using co-design of molecular and photonic structures can serve as an effective process to optimize the performance of dynamic nanophotonic devices. Finally, we discuss the potential research directions for conducting polymers and envision that they will provide future opportunities by new materials design and advanced characterization techniques.