BRIGE: Hindered-Diffusion Grayscale Surface Functionalization

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

This Broadening Participation Research Initiation Grant in Engineering (BRIGE) provides funding for the development of a novel nanoscale surface fabrication and patterning technique. This method utilizes the hindered diffusion of chemicals through a three-dimensional polymer mesh to create pseudo-grayscale functionalized surface patterns; the three-dimensional polymer substrate serves as a mask to control the diffusion path length of molecules from a liquid reservoir to the target patterning surface. In this manner, both the placement of surface-functionalized chemicals and the local density of these chemicals can be controlled. Experiments will be conducted in order to characterize mesh density and solute transport rates through polymers and this information will be used to derive predictive relationships correlating hindered diffusion rate to basic polymer and solute properties. These relationships will be used to generate numerical computer models of the described patterning mechanism, and the results will be validated experimentally. Finally, the combined numerical and experimental results will be used to create deterministic algorithms for selecting optimized polymer geometry and mesh density for any desired chemical/pattern combination. Selective deposition of chemicals can be used to modify a number of surface properties, including binding affinity, manufacturability, hydrophobicity, and immune response. The current state-of-the-art in surface patterning only enables the user to make microscale binary patterns, where regions are either completely absent of chemical modification or contain a single uniform chemical density. If successful, this research will represent an inexpensive method for producing surface patterns in a highly accurate manner with a level of geometric complexity that is unattainable with current methods. The focus on low-cost, widely-available materials would make this process immediately accessible to a large number of manufacturers and researchers. Applications for grayscale surface patterning are numerous and varied, including high-throughput binding studies for pharmaceutical development, portable biosensors for medical testing, control of fluid movement for microfluidics and self assembly, and quantitative studies of cell behavior. In addition, the hindered-diffusion studies and analytical models developed in this research will provide invaluable tools in the large number of fields governed by this transport mechanism, including tissue engineering, targeted drug delivery, and medical diagnostics.