BRIGE: Hindered-Diffusion Grayscale Surface Functionalization

这项扩大参与工程研究启动基金（bridge）为新型纳米级表面制造和图案化技术的发展提供资金。该方法利用化学物质通过三维聚合物网格的阻碍扩散来创建伪灰度功能化表面图案；三维聚合物衬底作为掩膜来控制分子从液体储存库到目标图案表面的扩散路径长度。通过这种方式，可以控制表面功能化化学品的放置和这些化学品的局部密度。将进行实验，以表征网状密度和溶质通过聚合物的传输速率，这些信息将用于推导与基本聚合物和溶质性质相关的阻碍扩散速率的预测关系。这些关系将用于生成所描述的模式机制的数值计算机模型，并将通过实验验证结果。最后，结合数值和实验结果将用于创建确定性算法，为任何所需的化学/图案组合选择优化的聚合物几何形状和网格密度。化学物质的选择性沉积可用于改变许多表面性质，包括结合亲和力、可制造性、疏水性和免疫反应。目前最先进的表面图案只能使用户制作微尺度的二元图案，其中区域要么完全没有化学修饰，要么包含单一均匀的化学密度。如果成功，这项研究将代表一种廉价的方法，以高度精确的方式产生表面图案，具有当前方法无法达到的几何复杂性水平。将重点放在低成本、广泛可用的材料上，将使大量制造商和研究人员能够立即获得这一过程。灰度表面图形的应用是多种多样的，包括用于药物开发的高通量结合研究，用于医学测试的便携式生物传感器，用于微流体和自组装的流体运动控制，以及细胞行为的定量研究。此外，本研究中开发的阻碍扩散研究和分析模型将为组织工程、靶向药物输送和医学诊断等由这种转运机制控制的大量领域提供宝贵的工具。

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.