Micromechanical mode-localized electric current sensor

Han Li; Zhao Zhang; Luhan Zu; Yongcun Hao; Honglong Chang

doi:10.1038/s41378-022-00375-1

Micromechanical mode-localized electric current sensor

Microsyst Nanoeng. 2022 Apr 14:8:42. doi: 10.1038/s41378-022-00375-1. eCollection 2022.

Authors

Han Li¹, Zhao Zhang¹, Luhan Zu¹, Yongcun Hao¹, Honglong Chang¹

Affiliation

¹ Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace, School of Mechanical Engineering, Northwestern Polytechnical University, 127 Youyi West Road, Beilin District, Xi'an, 710072 China.

Abstract

This paper outlines the design of a novel mode-localized electric current sensor based on a mechanically sensitive element of weakly coupled resonator systems. With the advantage of a high voltage sensitivity of weakly coupled resonator systems, the current under test is converted to voltage via a silicon shunt resistor, which causes stiffness perturbation to one resonator. The mode-localization phenomenon alters the energy distribution in the weakly coupled resonator system. A theoretical model of current sensing is established, and the performance of the current sensor is determined: the sensitivity of the electric current sensor is 567/A, the noise floor is 69.3 nA/√Hz, the resolution is 183.6 nA, and the bias instability is 81.6 nA. The mode-localized electric current sensor provides a new approach for measuring sub-microampere currents for applications in nuclear physics, including for photocurrent signals and transistor leakage currents. It could also become a key component of a portable mode-localized multimeter when combined with a mode-localized voltmeter. In addition, it has the potential for use in studying sensor arrays to achieve higher resolution.

Keywords: NEMS; Sensors.