A diode-less mechanical voltage multiplier: A novel transducer for vibration energy harvesting

This paper addresses the general area of electrical power collection and storage from vibrations. Energy harvesting from vibration sources through piezoelectric transduction is emerging as an interesting option for powering autonomous devices. In this research area, voltage multipliers are usually adopted to boost the voltage in order to reach a suitable level for the load circuits; these kind of devices are normally composed of diodes and capacitors in particular configurations. The novel approach proposed in this paper is called "All Mechanical Vibration Piezo-Electric Voltage Multiplier"; it allows the multiplication of the voltage produced by a piezoelectric transducer and it is based on a series of capacitors and mechanical switches (cantilever beams and stoppers) suitably connected. A suitable arrangement of switches, capacitors and piezoelectric transducers will result into the proposed mechanical voltage multiplier structure; no diodes are required and no control circuit is needed to allow the system to work. In this paper the working principle is introduced together with analytical models and numerical simulations. Experimental results are also reported to further confirm the validity of the proposed strategy: they have been obtained by using a macro-scale laboratory prototype. (c) 2014 Elsevier B.V. All rights reserved.