In reverse actuation, a voltage/electrical-current signal can be generated from applying a mechanical force to an electroactuator. Such processes are of interest in touch sensing and soft robotics applications. We develop a classical density functional theory of reverse actuation for polymer-electrolyte-composite electroactuators, which treats mobile cations in the same spirit as forward actuation (curving in response to applied voltage). The proposed framework is applied to electroactuators with micro-structured porous electrodes (with cylindrical or slit pores) and flat electrodes, the dynamic response of which has to be modelled differently. Open- and short-circuit operation modes are investigated separately. A detailed analysis of the proposed theory indicates the preferred architectures for sensing, depending on the operation regimes.