Optimized Design of MEMS Magnetic Field Sensors Based on the Piezoelectronic Effect and Nanogenerator Principle

Aiming at the key problems of noise level and power consumption that exist in most of the current MEMS magnetic field sensors, this paper takes the latest research contents and principles in the field of piezoelectronic effect and nanogenerator as the starting point, designs two improved MEMS magnetic field sensors, and verifies the effect and feasibility through relevant experiments. The improved magnetic field sensor based on the piezoelectronic effect shows that the piezoelectronic readout method can effectively eliminate the need for external preamplifiers for cantilever beam magnetic field sensors. Compared with the traditional piezoelectric readout, the piezoelectronic readout is able to measure lower noise peaks within a short integration time. Such an improvement reduces noise and power consumption and enables the sensor to operate self-powered, increasing energy conversion efficiency. An electret-based MEMS magnetic field sensor inspired by a novel nanogenerator is designed, and this improved method is able to reduce the resonance frequency of the cantilever beam sensor while providing higher response voltage and lower Q-factor, thus enabling measurements over a wide frequency range. The theoretical model constructed in this paper based on the non-resonant resonator agrees well with the experimental results. In summary, both of the above enhancement methods can effectively improve the energy conversion efficiency of the magnetic field sensor and reduce the power consumption and noise level to a certain extent, which is of great guidance for the design of high performance, low power MEMS magnetic field sensors.