Ultrasoft and High-Mobility Block Copolymers for Skin-Compatible Electronics

Adv Mater. 2021 Jan;33(4):e2005416. doi: 10.1002/adma.202005416. Epub 2020 Dec 14.

Abstract

Polymer semiconductors (PSCs) are an essential component of organic field-effect transistors (OFETs), but their potential for stretchable electronics is limited by their brittleness and failure susceptibility upon strain. Herein, a covalent connection of two state-of-the-art polymers-semiconducting poly-diketo-pyrrolopyrrole-thienothiophene (PDPP-TT) and elastomeric poly(dimethylsiloxane) (PDMS)-in a single triblock copolymer (TBC) chain is reported, which enables high charge carrier mobility and low modulus in one system. Three TBCs containing up to 65 wt% PDMS were obtained, and the TBC with 65 wt% PDMS content exhibits mobilities up to 0.1 cm2 V-1 s-1 , in the range of the fully conjugated reference polymer PDPP-TT (0.7 cm2 V-1 s-1 ). The TBC is ultrasoft with a low elastic modulus (5 MPa) in the range of mammalian tissue. The TBC exhibits an excellent stretchability and extraordinary durability, fully maintaining the initial electric conductivity in a doped state after 1500 cycles to 50% strain.

Keywords: block copolymers; organic field-effect transistors; skin-compatible electronics; stretchable organic electronics.