Research On Energy Harvesting With Piezoelectric Cantilever Structure

With the development of science and technology, research about a variety of portable power generation devices will become a new hotspot, which purpose is to replace batteries or recharge the battery automatically at some particular applications. A power generation device which make use of every principle of construction has its own characteristics and applications, the advantages of piezoelectric power generation devices lie in simple structure, no heat, no electromagnetic interference, ease of manufacture and realization of the structure of the small, integrated and so on, especially suitable for various types of sensing and monitoring systems. In this paper, we study theory and characteristic of piezoelectric cantilever structure, do the simulation about the classical energy acquisition circuit and the synchronous electric charge extraction circuit with the ORCAD / PSpice, compare and contrast test results with simulation results. Finally we design the energy storage circuitry and recharge lithium batteries. Specific studies of this article are as the following:1. By studying the piezoelectric effect and the piezoelectric equations we can obtain piezoelectric energy harvesting theoretical basis based on the piezoelectric effect, and choose the appropriate mode of piezoelectric vibration to harvest acquisition.2. Establish two typical structures, namely, single-crystal flakes cantilever and bimorph cantilever, on which we built the energy conversion model to arrive at theoretical formula. With Maple software doing numerical analysis, we can obtain the rule of its power performance which is influenced by the structure of Piezoelectric Vibrator size, material properties and thickness ratio.3. Design classics energy acquisition circuits and synchronous electric charge extraction circuit, and do the circuit simulation by the ORCAD / PSpice circuit simulation software, analyze the impact on the energy acquisition of different circuit load.4. Select the appropriate piezoelectric material and substrate materials, make a piezoelectric bimorph oscillator, build an experimental platform, harvest energy by the designed circuit, and compare experimental results with simulation results. Finally we design the energy storage circuit, recharge the lithium battery.