The team uses a new type of doped ZnO lead-free material, and strengthens the piezoelectricity of the material through processes such as polarization and annealing. Compared with the lead-free material LZO de-veloped last year, the piezoelectric coefficient d33 value is increased from 22.85pm/V to 80pm/V, and using ANSYS to simulate the best device struc-ture, successfully pioneered the development of lead-free piezoelectric MEMS 3-axis accelerometer, and integrated the low power readout circuit to establish the intelligent sensing control system required for the IoT.

The readout circuit using a current mirror based to form a transimpedance circuit structure. That is, the current is converted into a voltage, which is amplified by an inverting amplifier signal, and finally sent to a 10-bit 100KS/s SAR ADC. Compared with the traditional architecture, the current mirror based readout circuit has fewer current paths, so it can greatly reduce the power consumption.

The team used a new type of doped ZnO lead-free material and enhanced the piezoelectricity of the material through processes such as polarization and annealing. Compared with the lead-free material LZO developed last year, the piezoelectric coefficient d33 value increased from 22.85pm/V to 80pm/V, and used ANSYS to simulate the best device structure, successfully pioneered the development of lead-free piezoelectric MEMS 3-axis accelerometer, and integrate the current mirror based readout circuit developed by the team, under the condition of no loss of sensitivity and linearity, greatly reduce power consumption, thereby establishing the intelligent sensor control system required by the Internet of Things.

The team has successfully pioneered the MEMS three-axis lead-free piezoelectric accelerometer sensing system, which has the advantages of energy saving, environmental protection and high performance, and has been practically applied to the safety monitoring of unmanned vehicles and machine tools. In addition, three-axis accelerometer can be applied to positioning systems, Internet of Vehicle, automobile safety protection systems, and elderly safety protection systems. Therefore, in the modern era of booming sensors and environmental protection and energy saving, lead-free piezoelectric MEMS triaxial accelerometer have great commercial potential.