Incorporation of Piezoelectric Materials in Military Uniforms

This research deals with one of the possible ways of energy harvesting in military missions, using piezoelectricity as a fundamental basis for generating this energy. It harnesses the energy of the soldier when moving, especially on the battlefield or during long missions where a soldier needs external sources of energy to charge the batteries of their electronic devices. Since piezoelectric materials generate electrical potential at their terminals when mechanically stressed, this property makes them useful and favourable for realising this project. These materials can be either piezoceramic or piezopolymer and are available in various forms in the market. Therefore, to enhance the system’s efficiency, an electronic circuit for energy harvesting and self-powering is implemented to harvest the maximum energy generated by the piezoelectrics. Several circuits are studied and the best one is implemented in a Printed Circuit Board (PCB) prototype. Currents between 40 and $80~\mu $ A and voltages between 3.5 and 10.1 V are obtained before the voltage regulator. The maximum recorded power was approximately $812~\mu $ W, higher than the power reported in several recent articles. However, between 100 and $200~\mu $ W are obtained after the voltage regulation to 4.2 V. At the end of a day, the storage is expected to be around a unit of mAh, which could be enough to increase the autonomy of various devices used on missions, such as radios, GPS and torches, and even the possibility of activating emergency systems such as very lights or audible warning systems.