An anti-charge-interference three-dimensional electric field sensor

A major concern in the development of three-dimensional (3D) microelectromechanical system electric field sensors (EFSs) is space charge interference. With space charges in the surrounding environment, charges may accumulate at the surface of the EFS, which affects the accuracy of the electric field measurement. There is a lack of relevant mechanism research and solutions for this problem. Here, an anti-charge-interference 3D EFS is presented, which consists of three electric field sensing elements and a reference element. By establishing the model of the sensing element, the relationship of the electric field at the sensing chip with the distance between the sealing cap and the sensing chip is explored. The theoretical basis of the measurement method of the 3D electric field based on a coplanar structure is introduced. Then, the influence of charge accumulation is overcome by a differential calculation between the output signals of the reference element and sensing elements. The anti-charge-interference 3D EFS prototype is developed. Experimental results show that the measurement error of the anti-charge-interference 3D EFS is 4.01% and the linearity is better than 1% under an electric field of 0-50 kV m-1.