基于非线性动力学调控的高性能微电场传感器

As core components in electric field detection systems, electric field sensors have been widely applied in key fields such as high-voltage power transmission, atmospheric monitoring, electrostatic protection, and aerospace systems. In practical applications, the operational characteristics of resonator-based sensors are typically evaluated by assuming linearity of system responses. However, with growing demands for high sensitivity and resolution in electric field measurements, performance enhancement of electric field sensors has become a research focus in recent years. The applicability of traditional electric field sensors based on linear operating mechanisms is gradually being challenged. In this paper, we propose a novel approach to improve the performance of resonant microelectromechanical systems (MEMS) electric field sensors by harnessing nonlinear effects. We systematically explore approaches to controlling and leveraging nonlinear dynamics for boosting sensing capability under large-signal excitation conditions. Initially, the structural design of the sensor and electric field sensing principle are thoroughly analyzed. The core components of the sensor include a drive electrode, sensing electrode, movable shielding electrode, folded beams, and fixed anchors. Based on electrostatic induction and Gauss’s law, the sensitive structure generates an induced current proportional to the external electric field intensity, facilitating field strength measurement through current detection. The nonlinear behavior of the resonator and its control scheme are then introduced, with focus on the physical origins and manifestations of nonlinearity, such as geometric and material nonlinearities, as well as mode coupling effects. The following two analytical models are proposed: a linear vibration model for small-signal excitation, and a nonlinear model incorporating a cubic Duffing term for large-excitation conditions. Frequency response characteristics and sensitivity expressions are derived for both regimes, providing theoretical support for subsequent experimental validation to offer insights into the influence of nonlinearity on sensor performance. A 3D model of the sensor is constructed using COMSOL Multiphysics 6.0 to further investigate the nonlinear characteristics via structural simulation. A complete experimental platform is then developed, including a precision excitation circuit, differential current readout circuitry, and data acquisition and analysis system. This setup facilitates precise control of excitation amplitude and frequency, enabling systematic investigation of the resonator’s dynamic behavior under varying conditions. The experiments focus on the resonator’s nonlinear vibrations in its second-order mode. By adjusting parameters, such as excitation amplitude and bias voltage, we explore methods for effectively controlling the sensor operation within the nonlinear regime. The results reveal the impact of nonlinear vibration on sensor performance and demonstrate the remarkable enhancement of key metrics through meticulous tuning of nonlinear effects. Specifically, under optimized nonlinear operating conditions, the sensor achieves a maximum sensitivity of 4.69 mV·kV^–1·m and improved resolution of 0.46 V·m^–1. These findings confirm the feasibility and effectiveness of leveraging nonlinear mechanisms to enhance MEMS electric field sensor performance. This study offers a novel approach for achieving high-precision electric field detection and shows cases the considerable potential of nonlinear resonator technology in demanding application scenarios. With increasing performance requirements in fields such as smart grids, environmental monitoring, and aerospace systems, incorporation of controlled nonlinearity is expected to emerge as a powerful strategy for next-generation electric field sensor design.