Mechanoelectric effects in ionic gels

Certain fluorinated ion-exchange membranes, when swollen and suitably plate d by conducting electrodes, display a spontaneous curvature increasing with the applied electric field E-(1). There is also an inverse effect, where a n imposed curvature induces an electric field tin open circuit conditions). We present here a compact description of these effects in the linear regim e, and in static conditions: this is based on linear irreversible thermodyn amics, with two driving forces (E and a water pressure gradient del p) and two fluxes (electric current and water current). We also give some qualitat ive estimates of the three Onsager coefficients which come into play.