Sulfonated Copper Phthalocyanine/Sulfonated Polysulfone Composite Membrane for Ionic Polymer Actuators with High Power Density and Fast Response Time

Ionic polymer composite membranes based on sulfonated poly(arylene ether sulfone) (SPAES) and copper(II) phthalocyanine tetrasulfonic acid (CuPCSA) are assembled into bending ionic polymer actuators. CuPCSA is an organic filler with very high sulfonation degree (IEC = 4.5 mmol H⁺/g) that can be homogeneously dispersed on the molecular scale into the SPAES membrane, probably due to its good dispersibility in SPAES-containing solutions. SPAES/CuPCSA actuators exhibit larger ion conductivity (102 mS cm^-1), tensile modulus (208 MPa), strength (101 MPa), and strain (1.21%), exceptionally faster response to electrical stimuli, and larger mechanical power density (3028 W m^-3) than ever reported for ion-conducting polymer actuators. This outstanding actuation performance of SPAES/CuPCSA composite membrane actuators makes them attractive for next-generation transducers with high power density, which are currently developed, e.g., for underwater propulsion and endoscopic surgery.