Sensing Nanonewton Level Forces by Visually Tracking Structural Deformations

When assembling MEMS devices or manipulating biological cells it is often beneficial to have information about the force that is being applied to these objects. This force information is difficult to measure at these scales and up to now has been implemented using laser-based optical force measurement techniques or piezoresistive devices. In this paper we demonstrate a method to reliably measure nanonewton scale forces applied to a micro scale cantilever beam using a computer vision approach. A template matching algorithm is used to estimate the beam deflection to sub-pixel resolution in order to determine the force applied to the beam. The template, in addition to containing information about the geometry of the beam, contains information about the elastic properties of the beam. Minimizing the error between this elastic template and the actual image by means of numerical optimization techniques, we are able to measure forces to within +/- 3 nN. In addition, we also discuss how this ...

• Type: Conference
• Year: 2002
• Where: ICRA
• Authors: Michael A. Greminger, Ge Yang, Bradley J. Nelson
• Keywords: Cantilever Beam, ICRA 2002, Laser-based Optical Force, Robotics, Scale Cantilever Beam