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

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.