Fabrication And Characteristic Study Of Piezoelectric Energy Harvester With Stainless-stain Substrate

Piezoelectric Energy Harvester(PEH) is used for collecting energy. MEMS(Micro Electric Mechanical System) has advantages of small size, light mass, low cost, high reliability and high impact resistance, which could be applied to fabricate flexible PEH. Stainless Steel(SS) substrate has characteristics of high temperature resistance, high fracture toughness and easy deformation etc, which could offset traditional silicon substrate's frangibility under high vibration or large shape change. As stainless steel is conductor, it's essential to be insulated when it is used to be substrate. Due to piezoelectric mode vibration energy harvest method's advantages of high electromechanical conversion coefficient, environment harmony and being apt to scale down, which became one of the most popular research topics at the vibration energy harvest field. In addition, MEMS PEH's piezoelectric material is less, output power is small, so it's need to choose high power density piezoelectric material and fabricate thick film to generate larger power; SS is chosen to be the substrate with the big deformation and high impact resistance, which in favor of improving power output.With Electro-Hydro-Dynamic Atomization(EHDA) deposition being fit for thick film preparation, this method was used to fabricate 5?m thickness PZT film on the 30?m thick 304 SS substrate, after low-speed high temperature annealing, XRD test showed its crystal phase (110) preferred orientation and resulted in high quality perovskite structure. After polarizing the sample material, test showed the d33 mode piezoelectric constant is 70pC/N, the fine piezoelectric feature of this method fabricated was demonstrated. Three means used to fabricate insulate film, including PECVD for SiO2 film, EHDA deposition for PZT film and sol-gel for ZrO2.The piezoelectric cantilever mode was analysed, the SS substrate advantages was showed compared to silicon substrate. The voltage and power formula of d31 mode and d33 mode with SS substrates were derived, and simulated with scale and load effect factors. d31 mode PEH with SS substrate were designed and fabricated, got the max power with matched resistor. d33 mode SS substrates PEH were fabricated innovatively, the insulation, material annealing, photo etching, sputtering challenge were all resolved. The test power density of SS substrates PEH and silicon substrates PEH were compared, d31 mode SS substrates PEH power density is 2-20 times of the similar structure silicon substrate PEH,d33 mode SS substrates PEH power density is 2-10 times of d33 mode silicon substrates PEH. SS substrates PEH achieved high power density, improved MEMS PEH's application.