Research On Sensor Passive Self Powered Technology Based On Piezoelectric Principle

In recent decades,electronic devices such as sensors have gradually tended to the MEMS direction.As its volume tends to be miniaturized,the demand for power consumption of integrated circuits is gradually decreasing.In the traditional power supply the battery is characterized for short life span,not eco-friendly feature and difficulty in replacement,which increasingly emerges with time going by.In order to make up for the shortage of traditional battery power supply,effectively use the vibration energy in the environment,with mechanical-electrical conversion realize the passive self power supply of sensor and improve power supply efficiency,the piezoelectric energy harvester and its conversion circuit with a binaural cantilever beam structure are designed based on the piezoelectric principle.Meanwhile,as a result of the emergence of the circuit model of the collector,vibration mode,piezoelectric conversion circuit and the electrical output characteristics.The detailed information about it is as follows.First,the piezoelectric theory gives rise to the establishment of the electromechanical conversion model of the collector and the equivalent circuit model.Then,the influence of the length of the cantilever beam on the vibration frequency of the collector and the proportion of the piezoelectric sheet on the output performance is structured in terms of ANSYS software.This exploration reveals that notonly the first-order vibration frequency of the traditional cantilever beam piezoelectric energy harvester is greatly affected by the volume,but also the volume is difficult to be further reduced due to the frequency restriction.Moreover,there is an optimal ratio of the piezoelectric slice electrode to maximize the output voltage.In addition,forming a binaural cantilever beam piezoelectric energy harvester leads to synchronously execute in d33 and d31 vibration modes.Therefore,ANSYS simulation and experimental results make an implication that compared with ordinary cantilever beam piezoelectric energy harvesters,the first-order vibration frequency of the binaural piezoelectric energy harvester is reduced from 107.548 Hz to 77.6 Hz,and the amplitude is 27.8% with the same volume.However,the output voltage is increased from 5.37 V to 6.22 V with15.8% increase;when the piezoelectric plate electrode accounts for 40%,the output power is increased from 0.65 m W at 100% electrodes to 1.27 m W,an increase of 95.3%;the output power bears no relation to the connection method of the piezoelectric sheet.Consequently,with respect to the load capacity of the collector,the piezoelectric plate is about 4 times that of the parallel connection when the piezoelectric plates are connected in series,on the other hand the voltage output,when the piezoelectric plates are connected in series,it is about 2times that of the parallel connection,while the current output is about 1/2 times.Ultimately,the LTC3588-1 conversion circuit is planed,and the experimental inspection manifest that the output power of the circuit is 1.02 mw.Given that output power capability under the same conditions,its output capability is 1.67 times that of the parallel synchronous switch inductance circuit and 4.12 times that of the standard energy harvesting circuit.According to the different requirements of the sensor for the operating voltage,the output voltage can be selected from 1.8V,2.5V,3.3V,and 3.6V.Furthermore,when the circuit output is 3.6V,the wireless temperature sensor network is used for testing.