Atomic force microscope based biomolecular force-clamp measurements using a micromachined electrostatic actuator

作者：Torun Hamdi^*; Finkler Ofer; Degertekin F Levent

来源：Ultramicroscopy, 2012, 122: 26-31.

DOI：10.1016/j.ultramic.2012.07.023

• Atomic force microscopy
• Microsystems
• Force spectroscopy
• Single molecule mechanics

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 mu m 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 ms. 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.

• 出版日期2012-11