CAREER: Mechanically Activated Biological Adhesion

University Of Washington, Seattle WA

Investigators

Abstract

One of the recent discoveries in biological adhesion is the counterintuitive observation that some biological adhesive bonds, called catch bonds, are strengthened by tensile mechanical force. Adhesion via catch bonds offers the ultimate in reversible adhesion; gripping strongly under load but detaching when force is removed. The objective of this research is to determine design principles for mechanically regulated reversible adhesives based on a catch bond used by bacteria that normally live harmlessly in human intestines. In particular, this project will address the importance of the concentration and strength of adhesive molecules, how they are mechanically connected to the surface, and how force is applied between surfaces. This objective will be met with a mixture of theoretical calculations, stochastic multiscale simulations and experiments that measure adhesive behavior of bacteria or purified bacterial components integrated into the surface of small objects. Reversible adhesives are of technological interest. For example, like geckos walking up a wall, robots need to grip a surface under load but then let go again. Similarly, robots need to grip and release objects they manipulate. The medical community also wants adhesives for regulated drug delivery and for microfluidic diagnostic devices. The basic principles provided in this project can aid in the design of adhesives for drug-delivery nanoparticles, microfluidic devices, and medical robots. This project will also expose the pipeline of engineers to the stochastic principles and modeling techniques that become important at the nano-scale through exposure of underrepresented high school students and enrichment of the university curriculum.