title: Parallel force measurement with a polymeric microbeam array using an optical microscope and micromanipulator.
abstract: An image analysis method and its validation are presented for tracking the displacements of parallel mechanical force sensors. Force is measured using a combination of beam theory, optical microscopy, and image analysis. The primary instrument is a calibrated polymeric microbeam array mounted on a micromanipulator with the intended purpose of measuring traction forces on cell cultures or cell arrays. One application is the testing of hypotheses involving cellular mechanotransduction mechanisms. An Otsu-based image analysis code calculates displacement and force on cellular or other soft structures by using edge detection and image subtraction on digitally captured optical microscopy images. Forces as small as 250+/-50 nN and as great as 25+/-2.5 microN may be applied and measured upon as few as one or as many as hundreds of structures in parallel. A validation of the method is provided by comparing results from a rigid glass surface and a compliant polymeric surface.
authors.affiliation: Drexel University, Department of Mechanical Engineering and Mechanics, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
authors.forename: F Mert
authors.initials: FM
authors.lastname: Sasoglu
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bohl
authors.forename: Kathleen B
authors.initials: KB
authors.lastname: Allen
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Layton
mesh_terms: D000465:Algorithms; D001369:Axons / Q000502:physiology; D001696:Biomechanical Phenomena; D001699:Biometry; D020342:Finite Element Analysis; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D040542:Mechanotransduction, Cellular / Q000502:physiology; D008853:Microscopy / Q000295:instrumentation; D008954:Models, Biological; D009474:Neurons / Q000502:physiology; D013314:Stress, Mechanical