Investigation into the finger structure capacitor in the micro force measurement device

Abstract

Abstract The finger structure capacitor in the micro force measurement device was investigated by theory model analysis and comparative analysis with traditional parallel plate capacitor. The relationship between the micro force output and the distance variation between the electrodes was analysed. The micro force output of the finger structure capacitor and the traditional parallel plate capacitor were compared. Results show that the finger structure capacitor could produce stable micro force values when the finger structure parameters satisfied with x0/g >5. The output micro force value changed by less than 2% when the distance changed within 1mm in this range. Compared with traditional flat capacitors, the new finger structure capacitor greatly reduced the influence of the measurement and control uncertainty of the distance on the output micro-force values. The new finger structure capacitor device had little change in the output of micro force within 1mm distance variation and its output value changed with 1.7%, under the conditions of different applied voltages.