The Philadelphia Section of the STLE is pleased to award a $1,500 scholarship to second year Lehigh University graduate student Jasreen Kaur. Working under the direction of Professor Anand Jagota, and in conjunction with Cornell University and the Michelin Corporation, Kaur’s thesis project is titled “Meso-Scale Mechanisms for Friction in Structured Soft Materials: Elastic Hysteresis and Dislocation Arrays.” Kaur studies the friction between soft solids, such as elastomers for tire applications, or hydrogels for contact lenses. Kaur aims to develop and study shape-complementary surface structures that can be used to enhance or attenuate sliding friction in a manner inspired by such shape-complementary structures in Biology. She uses a complex flat-on-flat tribometer with six relative degrees of translational and rotational motion to carry out detailed experimental studies on the role of external pressure and misalignment on friction. One of the major discoveries of this work is that the interface between shape-complementary patterned surfaces spontaneously develops dislocation arrays. These arrays accommodate relative rotation and lattice mismatch. These are just like atomistic crystal dislocations, only at the micron scale instead of at Angstroms. They accommodate relative sliding by dislocation glide, and thus control frictional properties.
Kaur also carried out a detailed single-fibril sliding experiment to measure how elastic hysteresis provides energy loss to control macroscopic friction and has trained herself in sophisticated large-deformation finite element analysis used to model the experiments. Her current work is expected to be submitted for publication by the end of the summer.
Kaur is described as a quick study, hard-working, and a pleasure to work with and a natural experimentalist with the ability to handle complex mathematical and computational modeling.