Sticky and Slippery Materials

Noshir Pesika, Tulane University

The overall research theme in the Pesika group is the fabrication of “smart” surfaces and colloids.  In the first part of my talk, I will present some of our preliminary work on the use of highly monodispersed carbon microspheres as micro-bearings to lubricate surfaces.   The performance of these particles as an aqueous lubricant to reduce friction as well as minimize surface wear will be shown.  Potential applications for these particles in different formulations include an alternative to oil-based lubricants, and a replacement for synovial fluid.  In the second part of my talk, I will present our work on the design and fabrication of dry polymeric adhesives mimicking gecko adhesion.  The mechanisms by which geckos are able to adhere strongly yet detach easily and quickly will be shown.  In addition, I will demonstrate how mathematical models we have developed will be used to gear the fabrication of the next generation of dry adhesives.  Since the latter rely on van der Waals forces for adhesion, they can stick to almost any material in any environment or media, including in vacuum or under liquids.


(Left) Scanning electron microscope image of monodispersed 450 nm carbon spheres used as micrometer sized ball bearings.

(​Right) Hierarchical structures of the gecko adhesive system.  What can we learn from nature?