A Piconewton Forcemeter Assembled from Microtubules and Kinesins

A forcemeter capable of detecting piconewton forces was assembled from nanoscale building blocks, using a cantilevered microtubule as a beam of known stiffness, which is loaded by a second microtubule transported by kinesin motor proteins adsorbed to the surface and connected to the cantilevered microtubule by the link whose strength is to be determined. Due to the loading rate of less than 1 pN/s, this forcemeter is ideally suited to study the strength of biological receptor/ligand pairs, such as streptavidin/biotin.