NER: Developing a Nanoscale Strain Gauge

Texas Tech University, Lubbock TX

Investigators

Abstract

The objective of this project is to develop a nanoscale "strain-gauge" to measure flow-induced stresses at an interface. This molecular probe will be developed from a flexible macromolecule such as a single-strand DNA with fluorophores conjugated to each end. One end will be tethered to the phase interface and the other will extend freely into the deforming phase. In the presence of fluid flow, the molecule will change configuration, based on the local hydrodynamic forces. This change will be measured by fluorescent resonance energy transfer (FRET), which provides a nanoscale "ruler'" for measuring the distance between two fluorophores. FRET provides a sensitive means to measure distances between fluorophores that are 1-9 nm apart. This technique will initially be developed to map the flow field immediately adjacent to an interface as a means to study the effect of flow and/or deformation on interfacial properties. However, the technique will also be useful in studying the effects of flow in self-assembled monolayers and tethered macromolecules. It will also help verify multiscale modeling techniques by providing accurate measurements of molecular-scale response to macroscopic forces. Both undergraduate and graduate students will be directly involved in the development of the technique and will be trained in material science applications of fluorescent microscopy and in bioconjugate techniques. Results from the this study will also enhance the classroom experience for students in courses such as fluid mechanics by providing a visual example of flow/boundary interaction.