Measurement of Micro-Force Using the Vibration of a Spherical Latex Film

Abstract

Measuring the micro-nano-force is a hotspot in science and engineering. This paper focuses on a novel theory and method using the vibration amplitude of spherical film to measure the micro-force. The latex spherical film, with the diameter from 48 to 62 mm, is considered as sensing element, and the force or the mass is applied on the top of spherical film which results in the laser beam on the side surface of spherical film forming a bias. The bias measured by position sensitive detector sensor reflects the quantity of the micro-force or the mass. Experiments are designed to analyze the relation among the applied force, the diameter and thickness of spherical film, and vibration amplitude. Additionally, the fitting formula of these four parameters is obtained using the least square algorithm. On the full scale of 1.85–10.84 mN, this system can be used to measure the micro-force in the error range of −2.5% to 2.3%.