PVDF microbelts for harvesting energy from respiration

In this paper, we report a technique that uses piezoelectric polyvinylidene fluoride (PVDF) microbelts to convert the energy from low-speed air flow to electricity via their resonant oscillation. The micrometre thick PVDF thin films were fabricated by a top-down reactive ion etching process, where the thickness was controlled by etching time and the piezoelectric phase was well preserved. The thickness, air flow speed and electrical output relationship was predicted theoretically and characterized experimentally. The PVDF microbelts were able to generate sufficient electrical energy from low speed air flow for the sustained operation of small electronic devices. Their capability for harvesting energy from simulated respiration was also demonstrated.