|
Piezoelectric based energy harvesting has become a popular research interest for last few
years. This is due to the increasing demand for low-powered portable and wearable electronic
devices such as health monitoring sensors. This paper presents two polyvinylidene fluoride (PVDF)
based energy harvesters, which can be embedded in shoes to generate electric energy while human
walking. One of the harvesters is specially designed as a sandwich structure, placed under the ball of
foot, while the other one has curved or oval-shaped structure, placed under the heel of foot. Both
harvesters are developed and deployed appropriately in the sole to couple maximum mechanical
stress to the piezo-material and achieve high power output. The system was analysed, using
mathematical modelling and results are verified by performing experiments in the lab. It has been
observed experimentally that sandwich structured harvester produces 4.9 µW across a capacitor of
10 µF while walking at a speed of two step/second (2 Hz). However, for the same capacitor, the
curve-shaped harvester produces up to 5.625 µW power. Integrated output power of both energy
harvesters was 9.625 µW.
Keywords: piezoelectric; energy harvesting; PVDF; walking motion; smart materials. |
full paper (pdf, 1232 Kb)