Title: Characterizing the Dynamic Interactions of Biological and Biologically-Inspired Surfaces and Interfaces
Advisor: Jacob Israelachvili
Dynamic interactions of biological and biologically-inspired surfaces are difficult to characterize and study, yet are critically important for understanding the interfacial properties of systems. These dynamic phenomena can alter the forces experienced by the surfaces including adhesion, friction, and lubrication forces. Using a surface forces apparatus (SFA), new methodologies and analyses have been designed to study such dynamic interactions.
This presentation will discuss examples of two interesting systems: Gecko-mimetic adhesive behavior in diverse environments, and lipid domain rearrangements during membrane hemifusion.
Geckos have developed footpads that allow them to maintain their unique climbing ability despite vast differences in surfaces and environments. Likewise, successful gecko-inspired adhesives should exhibit adhesive and frictional performance across a similarly diverse range of environments. We have characterized the ‘frictional-adhesion’ behavior that enhances grip and facilitates easy detachment of the adhesives from rough surfaces and in humid environments in order to understand the underlying mechanisms necessary for successful adhesive applications.
The next system studied is membrane hemifusion, which is the core process in membrane trafficking and is essential for the transport of proteins and other biomolecules between cells. A newly developed fluorescence SFA technique was used to visualize and learn how lipid domains migrate to decrease the energy barrier to membrane hemifusion. The work presented has resulted in both application-based knowledge as well as more fundamental understandings of previously unobserved processes.