Microcantilever charged-particle flux detector

Abstract

A micromechanical sensor for charged-particle flux detection utilizing the extreme force sensitivity of microcantilevers is demonstrated with alpha particles. The latter create a charge buildup on an electrically isolated collection plate, a metallic sphere. The cantilever detector measures the electric field emanating from the charge collection sphere using variations in mechanical parameters. Results are compared with responses due to fixed voltages on the sphere. Parameters investigated include cantilever deflection due to total charge and frequency and damping rate variation due to electrostatic force gradient. The minimum detectable particle fluence using this technique was calculated to be around 1000 particles in air, or about 3.2×10−4 pC.

A micro resonant charge sensor with enhanced sensitivity based on differential sensing scheme and leverage mechanisms

“…Effect of environment disturbance is suppressed by the differential sensing scheme. The measured sensitivity of the two resonators are 3.31×10 -4 Hz/fC 2 and 1.85×10 -4 Hz/fC 2 respectively, and an overall sensitivity for the resonant charge sensor is 5.16×10 - Charge sensors can precisely measure electric charge with advantages of miniaturization and integration, and have been widely utilized in many applications such as aerosol particulate measurement, 1 bio-chemical analysis, 2,3 mass spectrometry, 4 nuclear research, 5 and space exploration. 6 Various methods have been demonstrated for charge sensing.…”

MEMS Electrometer With Femtoampere Resolution for Aerosol Particulate Measurements

“…Electrometer instruments are commonly used in tunneling microscopy, mass spectrometry, surface charge analysis, nuclear studies [5] and the development and delivery of pharmaceuticals [1]. Many types of electrometers exist, including single-electron transistors [6], nano-mechanical resonators at cryogenic temperatures [7], graphene resonators [8], and units based on vibrating reed devices [9].…”

Peer Reviewed: Microcantilever Transducers: A new Approach in Sensor Technology

“…However, environmental sensors in which deflection is caused by external electric or magnetic fields are also possible (22). For example, cantilevers were shown to bend in response to an electrostatic field induced by ionizing alpha particles (13).…”

“…An increasing number of recent reports confirms the potential of MC sensors for environmental and biomedical applications, and the multifaceted functionality of MCs indicates their uniqueness as compared with more traditional sensor designs (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17).…”