Artificial human joint for the characterization of piezoelectric transducers in self-powered telemedicine applications

This paper introduces an artificial human joint working as testing machine for the experimental characterization of piezoelectric transducers for wearable applications. The diffusion of portable medical devices and low-power communication systems for telemedicine and telehealth is leading to the development of self-powered diagnostic systems supplied by small wearable generators. Laboratory tests are needed before the validation on human body for instance, to measure electric outputs, material properties and transducers reliability, as well as dedicated test benches must be designed and built. This work contributes to define experimental methodologies and test benches for the characterization of materials and electro-mechanical response of piezoelectric transducers. The proposed testing machine contributes to improve the effectiveness of harvesters design by providing preliminary data about performances, endurance and reliability. The same data are not easy to obtain from direct tests on the body due to the long test duration and the high repeatability and accuracy in imposing the movements. Additionally, the managing and control of multiple testing parameters is also needed, e.g. in design-of-experiments approaches. The functionality of the testing machine, which has been previously designed and built, has been proved with some qualitative measurements on piezo foil transducers coated with polymer.