Testing and evaluation of stretching strain in clamped-clamped beams for energy harvesting

摘要

In this paper, evaluation of stretching strain capabilities to harvest energy from a piezoelectric clamped-clamped beam is theoretically modeled and experimentally tested. The utilization of stretching strain has many advantages as: elimination of any substrate material, and the simple electrode configuration. The doubly clamped structure exhibits a highly nonlinear frequency response (Hardening Duffing) that widens the bandwidth during the frequency up-ward sweep. The wide bandwidth makes it suitable for practical applications. A design of 53.5 mm(3) (29.7 mm(3) piezoelectric material + 23.8 mm(3) proof mass) energy harvester was tested using PVDF (polyvinylidene fluoride) that can generate up to 15 mu W from vibrations of 0.5g at 128 Hz and 2 M Omega load. The design can also generate up to 41 mu W from vibrations of 1g at 140 Hz and 2 M Omega load.