Related Experiment Video
Updated: Jun 17, 2026
10:15
Atomic Force Microscopy Imaging and Force Spectroscopy of Supported Lipid Bilayers
Published on: July 22, 2015
Membrane-based actuation for high-speed single molecule force spectroscopy studies using AFM
Krishna Sarangapani1, Hamdi Torun, Ofer Finkler
1Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
European Biophysics Journal : EBJ
|January 8, 2010
Summary
New polymer membranes enable atomic force microscopy (AFM) at ultra-high speeds. This overcomes hydrodynamic forces, allowing faster single-molecule unbinding force measurements for enhanced biological studies.
Area of Science:
- Biophysics
- Materials Science
- Nanotechnology
Background:
- Atomic force microscopy (AFM) dynamic force spectroscopy measures molecular interactions.
- Hydrodynamic forces limit AFM cantilever performance at high pulling speeds (>10 microm/s).
- Viscous drag significantly impacts unbinding/unfolding force measurements.
Purpose of the Study:
- To develop a method to overcome hydrodynamic limitations in AFM.
- To enable high-speed AFM measurements (>100 microm/s) with minimal viscous drag.
- To achieve higher bond loading rates for single-molecule force spectroscopy.
Main Methods:
- Fabrication of polymer-based membranes for AFM cantilever actuation.
- Computational fluid dynamics (CFD) simulations using FLUENT software.
- Experimental unbinding force experiments using human antibodies.
Main Results:
- Membrane actuators enable AFM cantilevers to operate at speeds >=100 microm/s.
- CFD simulations predict and experimental results confirm reduced drag forces with membrane actuators.
- Achieved bond loading rates of >=10(6) pN/s, an order of magnitude higher than conventional systems.
Conclusions:
- Polymer-based membranes effectively mitigate hydrodynamic forces in high-speed AFM.
- This technology significantly enhances the achievable bond loading rates in single-molecule force spectroscopy.
- The developed method opens new possibilities for studying rapid molecular interactions.
