Christine Luscombe (OIST): "The intriguing characteristics of indacenothiophene-based copolymers and their potential use in flexible devices"

Christine Luscombe, a Professor at the Okinawa Institute of Science and Technology in Okinawa, Japan, holds a PhD from the University of Cambridge. Her early work, meriting the Syngenta Award for best organic chemistry project, involved surface modifications using supercritical carbon dioxide. Postdoctoral research at UC Berkeley under Prof. Jean Fréchet led to her interest in semiconducting polymers for organic photovoltaics. Joining the University of Washington in 2006, her work gained recognition and she secured the NSF CAREER Award, DARPA Young Faculty Award, and the Sloan Research Fellowship. Recent honors include election to the Washington State Academy of Sciences (2020) and Society of Polymer Science Japan Science Award (2022). She has published over 140 papers, primarily on semiconducting polymers and microplastics research. Luscombe actively contributes to the scientific community, serving on editorial boards for numerous journals, including as an Associate Editor for Macromolecules.

Abstract: Increased interest in deformable electronic devices such as e-skin, wearable sensors, stretchable organic photovoltaics, soft robotics, and stretchable organic field effect transistors warrants the development of intrinsically deformable electronic materials. Conjugated polymers (CPs) can be utilized as a semiconducting material within deformable devices because of their tunable electronic properties and wide variance of mechanical properties. As is the case for commodity polymers and their applications, a single CP often does not satisfy the various optoelectronic, semiconducting, or mechanical requirements imposed by a given deformable electronic application. Polymers with different elastic moduli, elongation at breaks, rheological properties, stress–strain profiles, solubilities, optoelectronic profiles, and hole mobilities are, thus, required to fulfill the various needs of certain applications. This warrants the further development of structure–property relationships for CP systems to guide the design of new intrinsically deformable CPs to address this need.

Indacenodithiophene (IDT) copolymers are a class of conjugated polymers that have limited long-range order and high hole mobilities, which makes them promising candidates for use in deformable electronic devices. Key to their high hole mobilities is the coplanar monomer repeat units within the backbone. The long alkyl chains on the IDT unit limit their long-range order. The combination of the rigid polymer backbone and flexible side chains endow the polymers with interesting mechanical properties.

In recent years, we have synthesized a range of IDT-based copolymers most of which have ended up with mechanical properties that we did not anticipate. In this presentation, the unique features of the IDT-based copolymers will be discussed.