Toward single-molecule electromechanical actuators

Herein we report the design, synthesis, and properties of a novel electromechanical actuator, poly(cyclooctatetrathiophene). This system integrates both a conducting polymer and a [4n]annulene repeat unit. The ability of [4n]annulenes to undergo a conformational change as a function of redox state is well known, and allows poly(cyclooctatetrathiophene) to, in principle, expand and contract via redox-induced changes in the length of the repeating unit. Thus, electromechanical actuation in this system is an intrinsic property of the individual chains, not a bulk property of the material. The ultimate goal is to demonstrate single-molecule electromechanical actuation.