Adaptation of a solid-state marx modulator for electroactive polymer

Electroactive polymers show promising characteristics, such as lightness, compactness, flexibility, and large displacements, making them a candidate for application in cardiac assist devices [1], robotics and other compact applications. This revives the need for quasi-square wave voltage supply switching between 0 and several kilovolts. It must be efficient in both the charge and discharge phases [2] and compact. The high access resistance, associated with compliant electrodes, represents an additional difficulty. Here, a solid-state Marx modulator is adapted to cope with electroactive polymer characteristics, taking advantage of an efficient energy transfer over a sequential multistep charge/discharge process. To ensure compactness, efficiency, as well as the needs of an implanted device, a wireless magnetic field-based communication and power transfer system has been implemented. This work demonstrates the benefit of this design through simulations and experimental validation on a cardiac assist device. At a voltage of 7 kV, an overall efficiency of up to 88% has been achieved over a complete charge/discharge cycle.