Scavenging energy from human activities using piezoelectric material

Smart solutions for energy generationare required for a sustainable future. Many studiesand researches are in the pipeline to forge new reliable and affordable techniques for electricity generation from natural sources, particularly in low power generation due to mass consumption of small and portable electronic devices. In this context, piezoelectric material is seen as a potential candidate for energy generation since it has an outstanding property of converting kinetic energy into electricity. In this study, a prototype termed as Vibration Energy Harvester (VEnH) is developed to assess its performance in generating electricity from a vibration source. The prototype consists of a cantilever beam with a piezoceramic attached at half-length of the cantilever beam, a DC motor for emulationof the vibration produced by human footsteps and a microcontroller. Whena continuous force is applied to the VEnH, the cantilever beam experiencesdeformations and thus induces electricity. Two tests were conducted, namely the input force magnitude variation (1mm - 18mm) tests and the input frequency increment (0Hz - 10Hz) tests. The results showed that the output voltage was consistently increased proportional to the applied input displacement until it reacheda saturationpoint. In an optimal condition, about 5.4 Volts was generated before it reached the saturation point. Nonetheless the saturation point varies according to the input excitation frequency and it is discovered that the optimal input excitation frequency is of 4.2Hz. The results have potently showed the energy generation via VEnH isreliable and consistent, and thus upholds the positive prospective for its applications to harvest energy from human activities. (C) 2014 The Authors. Published by Elsevier Ltd.