Hydraulic valves design for the operation of an in-ear energy harvesting system

This paper demonstrates the concept and design of a hydraulic-piezoelectric self-actuated frequency up conversion system for energy harvesting. Two pistons actuate a bistable oscillator associated to a piezoelectric transducer allowing a low frequency hydraulic excitation to be efficiently converted into electric energy. An innovative concept of hydraulic passive valves based on flexible tube buckling is presented.