Feasibility of piezoelectric energy harvesting chip based sensor for human physical activity monitoring

Abstract

This research experimentally reveals a sensor application in a future home in the IoE era that the possibility of using piezoelectric energy harvesting chips placed under the shoe insole for sensing foot pressure, or human activity while walking. Commercially available flat type piezoelectric PVDF polymer film chips were used for experiments. Two experiments are conducted: i) output voltage vs. chip bending, and ii) output signal captured by chips under insole while walking. Results obtained are; for i), output voltage measured was 0.09–0.17 V peak average increase per one mm deformation. Output was basically linear to the amount of deformation. However, its characteristics depend on the chip. And, ii) found that higher speeds yielded higher counts over the threshold signal level that might correspond to the activity level. Therefore, a piezoelectric energy harvesting chip was found to be feasible as a human activity sensor with less energy.