Video analysis of polymerized micro-cantilever deflected by the laser trap.

摘要

Elastic micro-cantilever of 30-micrometer size is repeatedly deflected/released by optical tweezers trap, recorded by ahigh-speed camera (500 frames/sec) and subsequently processed off-line. This paper evaluates the position detectionmethods of the cantilever head, which is distorted by a diffraction pattern. We developed and tested four methods in ourVideoAnalyser software - radial extremes, Hough transform, local corner tracking, and voting normal lines. The timedependence of the head position contains the information about the properties of both: cantilever material and thesurrounding environment. Averaging of aligned graphs corresponding to individual cycles significantly improves thesignal-to-noise ratio.