Mechanoelectric effects in ionic gels

¹ Collège de France - 11 place M. Berthelot, 75231 Paris Cedex 05, France
² School of Engineering and School of Medicine, University of New Mexico Albuquerque, NM 87131, USA

Corresponding author: pierre-gilles.degennes@espci.fr

Received: 30 September 1999
Accepted: 15 March 2000

Abstract

Certain fluorinated ion-exchange membranes, when swollen and suitably plated by conducting electrodes, display a spontaneous curvature increasing with the applied electric field . There is also an inverse effect, where an imposed curvature induces an electric field (in open circuit conditions). We present here a compact description of these effects in the linear regime, and in static conditions: this is based on linear irreversible thermodynamics, with two driving forces ({E} and a water pressure gradient ) and two fluxes (electric current and water current). We also give some qualitative estimates of the three Onsager coefficients which come into play.