Design And Manufacture Of Vibrational Power Harvesting MEMS Devices Based On Piezoelectric And Electromagnetic Effect

Micro energy technology with high output power density is urgently required, and is animportant developing direction of intelligent MEMS devices system. MEMS devicesvibration-driven have the characters of small volume, light weight, high energy density, longlife, non-pollution, a strong environment adaptation. It is expected to provide high reliability,long electricity for the micro-system in the field and posting structure, the wireless sensornetwork, portable microelectronics products.In this paper, vibrational power harvesting MEMS devices based on piezoelectric andelectromagnetic effect are studied. It transforms environment vibration into energy, andintegrates the advantage of piezoelectric and electromagnetic generator, improves the outputof voltage and current. It has the new four cantilever beam-center quality block structureinstead of traditional single cantilever structure, and the PZT thin film is prepared on eachcantilever, which increases the piezoelectric power generation energy and improves theoverall energy density and output efficiency of the system. At the same time, it has lownatural frequency and is easy to reach to environmental vibration resonance, which produceshigh-density electric energy. It provides a new idea for the new MEMS devices research.The mechanical and electrical conversion effect of piezoelectric materials andelectromagnetic energy conversion mechanism are studied in micro-nano scales. Thestructural model of vibrational power harvesting MEMS device is established. The staticanalysis, modal analysis, harmonic response analysis of the MEMS devices structure by finiteelement analysis software ANSYS 11.0 is analyzed. The optimal size of the MEMS devicesstructure is obtained, combining micro-machining process constraints. The heterogeneousintegration of PZT thin film materials and 3 inches Pt (111) / Ti/SiO2/Si (100) substrate isachieved by sol-gel process. The mask layout is designed. The four cantilever beam-centerquality block structure, a permanent magnetic column, electrode and annular induction coilsare designed and machininged by the bulk silicon processing technology, surfacemicromachining process, LIGA process, bonding process. The integrated manufacturing ofvibrational power harvesting MEMS devices based on piezoelectric and electromagneticeffect is realized. The test system is built. The performance of vibrational power harvesting MEMS devices based on piezoelectric and electromagnetic effect is tested preliminarily.It provides the theory basis and the technical guidance for practical application of vibrationalpower harvesting MEMS devices based on piezoelectric and electromagnetic effect in microelectrical and mechanical devices and system.