Cantilevers-on-membrane design for broadband MEMS piezoelectric vibration energy harvesting

[摘要] Most MEMS piezoelectric vibration energy harvesters involve either cantilever-based topologies, doubly-clamped beams or membrane structures. While these traditional designs offer simplicity, their frequency response for broadband excitation are typically inadequate. This paper presents a new integrated cantilever-on-membrane design that attempts to both optimise the strain distribution on a piezoelectric membrane resonator and improve the power responsiveness of the harvester for broadband excitation. While a classic membrane-based resonator has the potential to theoretically offer wider operational frequency bandwidth than its cantilever counterpart, the addition of a centred proof mass neutralises its otherwise high strain energy regions. The proposed topology addresses this issue by relocating the proof mass onto subsidiary cantilevers and integrates the merits of both the membrane and the cantilever designs. When experimentally subjected to a band-limited white noise excitation, up to approximately two folds of power enhancement was observed for the new membrane harvester compared to a classic plain membrane device.

[发布机构] Faculty of Science and Engineering, Thornton Science Park, University of Chester, Chester; CH2 4NU, United Kingdom^1;Department of Engineering, University of Cambridge, Trumpington Street, Cambridge; CB2 1PZ, United Kingdom^2

[效力级别] 能源学

[关键词] Broadband excitation;Doubly clamped beam;Operational frequency;Piezoelectric membranes;Piezoelectric vibration;Power enhancement;Strain distributions;White noise excitation