CAREER: Molecular Basis for Viscoelastic Response on Nano-Mechanical Biosensors

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

The objective of this Faculty Early Development (CAREER) Program research is to provide understanding of fundamental mechanisms that govern energy dissipation in MEMS/NEMS resonators operating in aqueous environments to enable design of highly sensitive biosensors. This promising sensor techonology is currently limited by lack of theoretical framework that relates the change in resonance frequency to a specific target molecule binding to a surface. Large scale atomistic simulations based on the molecular dynamics technique will be employed to address this issue. Specifically, molecular events and internal dynamics at the solid-liquid interface will be characterized to understand how the nanometer-scale structure impacts viscoelastic properties. The effect of environmental conditions, e.g., temperature and ionic strength, on energy dissipation will be characterized and quantified. Changes in resonance frequencies will be determined as a function of the molecule type, length, and density distribution of ions. Conditions that lead to true or apparent slip at the interface will be established. A close collaboration with an experimental group will allow for validation of predictions made by the models and will ensure a quick dissemination of scientific findings. The outcome of this project will be establishing of relationships between molecular structures at the solid/liquid interface and the mechanical response of resonators. The ability to predict relative resonance shifts will enable design of structures capable of real-time biosensing and will lead to basic understanding of wear and related issues. The educational component of this grant includes interdisciplinary training of undergraduate and graduate students enrolled in courses that are being developed by the PI. Computer-generated demonstrations of concepts in nano-biomechanics will be used as lecture examples. Scientific findings of this research will be disseminated through the Atomic scale Friction Research and Teaching Synergy Hub (AFRESH), which is an NSF-funded multi-institutional virtual organization that brings together researchers and educators in the field of nanotribology. Additionally, the PI will collaborate with social scientists to create an outreach program to the general public who may have some preexisting biases against developments in nano-biotechnology. Through round-table and panel discussions a non-hostile environment will be created in which a dialogue about science is encouraged among participants with diverse ideological backgrounds.