Challenges in Nanoburnishing Precision Sawtooth Grooves

Tuesday, May 22, 2018 - 2:00pm
3110 Etcheverry Hall
Subhalakshmi Kumar, Ph.D.

Senior Research Scientist

Inprentus, Inc.


Ideal plastic deformation under a dynamic contact is required for precision nano manufacturing products like mechanically-ruled diffraction gratings. Controlled micro and nanoscale deformations at the metal-air interface under a sliding contact remain poorly understood but an outstanding nano-burnishing challenge. Bulk understanding of material flow breaks down for thin films and the static load picture developed for nano-indentation, for example, fails to give intuition for the dynamics involved.  Inprentus manufactures mechanically ruled blazed diffraction gratings for applications ranging from VUV to soft X-rays and in this talk, I will outline surprising empirical observations and working hypotheses we have developed at the company towards creating these asymmetric sawtooth shaped grooves.  Modeling these processes is key to fundamental understanding of material flow mechanisms at these length scales and will impact applications where diffraction gratings are vital. These include cutting-edge materials physics research, synchrotron science, space science, high powered lasers and semiconductor lithography light sources.


Subhalakshmi Kumar is a polymer physicist by training, focusing on structure-property dynamics in soft matter.  For her Ph.D. with Steve Granick at Material Science and Engineering at Illinois, she used high resolution optical techniques to probe interfacial polymer dynamics with single-molecule precision. In 2015, as a postdoctoral research associate in the DOW-Illinois University Partnership Initiative she worked on the New Approaches for Controlled Release of Active Materials project.  Here, she developed real time, four-dimensional confocal microscopy to study drying dynamics of water based, low VOC latex thin films with single-particle precision. Subha joined Inprentus in Sept. 2017 as a Senior Research Scientist. Her work involves understanding nano-burnishing process - tool geometry effects, interfacial plastic deformation in gold thin films, contact tribology and effects of mechanical ruling parameters on groove formation.


Hosted by: Assistant Professor Hayden Taylor, 6159 Etcheverry Hall, 510- 642-4901,