Tapping force measurement by using micromachined cantilevers and laser systems

摘要

Measurement of periodical contact force (tapping force) of the tapping stylus is very important for performance evaluation of soft material profilometry. So far, simulations are performed to estimate the force, and force calibration cantilevers are used to measure small contact force of AFMs. Since the tapping stylus uses larger tapping force compared to AFMs, micro cantilevers made of glass are developed for the force measurement of range from mN to μN. The levers are calibrated by using a standard cantilever made of silicon, which is fabricated by a micromachning process. A laser interferometer system is used for the calibration of glass cantilever spring constant. A laser Doppler vibrometer is used to measure the velocity of the cantilevers, and the force is estimated from the velocity signal by an integration.