title: Atomic force microscope based biomolecular force-clamp measurements using a micromachined electrostatic actuator.
abstract: The authors describe a method for biomolecular force clamp measurements using atomic force microscope (AFM) cantilevers and micromachined membrane-based electrostatic actuators. The actuators comprise of Parylene membranes with embedded side actuation electrodes and are fabricated on a silicon substrate. The devices have a displacement range of 1.8 μm with 200 V actuation voltage, and displacement uncertainty is 0.8 nm, including the noise and drift. The settling time, limited by the particular amplifier is 5 ms, with an inherent range down to 20 μs. A force clamp measurement setup using these actuators in a feedback loop has been used to measure bond life-times between human IgG and anti-human IgG molecules to demonstrate the feasibility of this method for biological experiments. The experimental findings are compared with a molecular pulling experiment and the results are found to be in good agreement.
authors.affiliation: Department of Electrical and Electronics Engineering, Bogazici University, Bebek, TR-34342 Istanbul, Turkey. hamdi.torun@boun.edu.tr
authors.forename: Hamdi
authors.initials: H
authors.lastname: Torun
authors.forename: Ofer
authors.initials: O
authors.lastname: Finkler
authors.forename: F Levent
authors.initials: FL
authors.lastname: Degertekin
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000032:analysis / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry; D004867:Equipment Design; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000378:metabolism; D055595:Mechanical Phenomena; D018625:Microscopy, Atomic Force / Q000295:instrumentation* / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012984:Software; D055672:Static Electricity; D014992:Xylenes / Q000737:chemistry
chemical_list: D000888:Antibodies, Anti-Idiotypic; D001672:Biocompatible Materials; D007074:Immunoglobulin G; D011108:Polymers; D014992:Xylenes; C048844:anti-IgG; C011055:parylene