Current-generating 'double layer shoe' with a porous sole.

We present a principle and a simple theory of a novel reverse electroactuator, in which the electrical current is generated by pumping an electrolytic liquid into nonwetting pores of a polarized electrode. The theory establishes the relationship between the variation of external pressure and the electrical current. The effective current density is amplified by the high porosity of the electrode. The suggested principle can be implemented into the design of a shoe which will generate an AC current simply by walking. Estimates of typical parameters and operation regimes of such a device suggest that one can easily generate a peak current density of ~17 mA cm(-2). This would produce some 1.7 A from each shoe at 0.65 W average power density, without hampering walking.