Mechanical Characterization of Biomolecules in Liquid using Silicon Tweezers with Subnanonewton Resolution

Molecular biophysicists seek to understand how biological systems work through mechanical or electrical characterizations performed at the molecular scale. From this perspective, we have devised a silicon-based micromechanical tool for stress-strain measurements of molecular fibers and demonstrated micro manipulation and biomechanical characterization of DNA bundles in a liquid solution. By combining this instrument with a microscopic displacement measurement technique based on Fourier transform image processing, we could achieve a force resolution of 25 pN - a level which is within the single-molecule sensing range - and validate a novel approach for stress-strain measurements.