A Micromachined Electrometer With Room Temperature Resolution of 0.256 e/ $\surd$ Hz

Electrostatic charge sensing is of fundamental significance for physical, chemical, and biological detection devices. Almost all current approaches with high resolution are based on single-electron tunneling transistor electrometers that must be operated under ultra-low temperature (<; 10 K) and field-effect transistor electrometers with a dynamic range of only several electrons. In this paper, a micromachined resonant electrometer based on four-degrees-of-freedom weakly coupled resonators is reported to realize room temperature operation and a large measurement range (over 500,000 electrons) and dynamic range of 136.7 dB with resolution of 0.256 e/√Hz. To the best knowledge of the authors, the resolution is the highest level of any micromachined electrometers.