RUI/Collaborative Research: The Molecular Origins of Friction - A Study Across Velocity Regimes of Phosphonate Monolayers on Alternative MEMS-Type Surfaces

Luther College, Decorah IA

Investigators

Abstract

The purpose of this collaborative project is to combine the resources of three institutions to study the frictional properties of molecularly-thin films for a wide range of sliding speeds. These films, known as self-assembled monolayers (SAMs), will be composed of phosphonic acid molecules, long-chain carbon-based molecules that include phosphorous. These SAMs will be attached to oxidized metal surfaces and provide a model system for exploring how friction depends on molecular structure and the surface to which the molecules are attached. With intensive involvement of undergraduate students, Prof. Erin Flater at Luther College and Prof. Brian Borovsky at St. Olaf College will compare frictional measurements performed using two distinct micro/nanoscale friction measuring devices, an atomic force microscope and an integrated nanoindenter - quartz microbalance system, respectively. Prof. W. Robert Ashurst at Auburn University will prepare the samples in advance, to create identical frictional interfaces for study at Luther and St. Olaf. Understanding the frictional properties of SAMs provides information about the nature of friction in general, and the results of this collaborative research program will help bridge the scientific and technical areas of friction research. As mechanical devices are made smaller in size, their functionality is limited by surface phenomena, such as friction and adhesion. In this way, low friction phosphonate SAMs may provide an alternative pathway for the development of microscale devices. This project exemplifies the dedication of St. Olaf College and Luther College to provide undergraduate students with access to mentored research opportunities and modern instrumentation. The techniques developed will be incorporated into existing advanced laboratory courses, maximizing the educational impact of the collaborators? research programs.