Micropatterned and NanoTextured Surfaces: From Self-Cleaning to Selective Particle Direction

0932719 Santore该项目创建的材料，引导流动的粒子在其表面上，沿着不同的路径取决于粒子类型。 这些表面将具有选择性的粘附性和自清洁性，并有可能产生颗粒敏感的光学信号。 该程序采用了各种颗粒（反应胶囊，药物输送载体，细胞，细菌），0.1 - 25微米（微米）大小的模型。 包含各种长度尺度的图案的表面设置粒子方向、路径和运动特征（滚动、滑动、跳跃、停止）。 工程表面将用于微流体方案，根据尺寸、形状、柔软度和表面化学性质连续在线分选和分离细胞和其他颗粒。 智力优点：该计划开发了一种机制，该机制由流体动力学和界面力相结合而产生，后者独特地由与颗粒相互作用的化学纳米纹理和纳米形貌特征而产生。 这些纳米纹理赋予选择性（基于局部颗粒曲率，柔软度和化学功能性），并控制遇到表面的流动颗粒的运动特征。 这些表面的一个重要制度是，持续滚动发生在纳米纹理。 在这里，具有选择性和可逆结合的动态粘附允许颗粒在表面上连续加工。 然后，添加不同表面化学性质（包括一些图案化区域上的纳米纹理）或形貌的微米级图案，允许通过其粘合特性和与表面的净接触面积区分的不同颗粒群在表面上沿不同方向转向。 该程序将开发引导不同类型的颗粒沿着不同表面路径的图案，作为基于其特征的细微差异分离颗粒的手段：尺寸，局部形状/粗糙度，近表面模量，净电荷和表面电荷分布。 该程序结合了实验和模拟，以开发应用驱动的设计规则，并最大限度地提高分离效率。该程序的新奇在于使用表面图案和纳米纹理，通过流体动力学和表面相互作用来操纵颗粒。 连续颗粒滚动的范例在一个表面上的操纵和分离的颗粒是一个新的和强大的想法，它利用了一个新的界面机制。 迄今为止，该机制已在简单的治疗中建模，但尚未得到实验证实。 除了科学上的复杂性外，受控颗粒轧制在技术上也具有变革性，因为它有利于连续而不是批量处理。此外，在复杂的多维变量空间中描述粘合剂行为的状态空间方法作为工程方法是高度变革的。 表面力/流问题一般不适合通过无量纲组简化，状态空间方法提供了机会，以开发简单的比例法则，适用于应用驱动的设计。 更广泛的影响：除了在材料和运输工程之间的界面研究复杂动态问题的变革性方法外，该计划还将改变需要精确分离和表征微米级物体的技术。 生物医学和制药应用将受益于便携式细胞分选设备的最终发展，需要最少的支持仪器和技术人员的时间。 该计划也有可能大修战略的海洋防污涂料的设计，通过其纳入材料设计的流体动力学考虑。该计划支持在材料和工程的交叉多学科基础课程的持续发展。 努力保持多样性和改善代表性不足和经济弱势群体的参与将通过参与马萨诸塞大学（MRSEC，ICE，NEAGEP）的几个现有组织和团体来促进，这些组织和团体举办招聘旅行和研讨会。

0932719SantoreThis project creates materials that steer flowing particles over their surfaces, along different paths depending on particle type. The surfaces will be selectively adhesive and self cleaning, with the potential to generate particle-sensitive optical signals. The program employs models for a variety of particles (reactive capsules, drug delivery vehicles, cells, bacteria), 0.1 ¡V 25 Ým (micron) in size. The surfaces, which contain patterns at a variety of length scales set the particle direction, path, and motion signature (rolling, slipping, skipping, arrest). The engineered surfaces will find use in microfluidic schemes for continuous on-line sorting and separation of cells and other particles based on size, shape, softness, and surface chemistry. Intellectual merit: The program develops a mechanism that results from combined hydrodynamic and interfacial forces, where the latter uniquely result from chemical nanotextures and nano-topographical features that interact with the particles. These nanotextures impart selectivity (based on local particle curvature, softness, and chemical functionality) and control the motion signature of flowing particles that encounter the surface. An important regime for these surfaces is that where sustained rolling occurs over nanotextures. Here dynamic adhesion with selective and reversible binding allows particles to be continuously processed over the surface. Then the addition of micron-scale patterns of varied surface chemistry (including the nanotextures on some patterned regions) or topography, allows different particle populations, distinguished by their adhesive character and net contact area with the surface, to be steered in different directions over the surface. This program will develop patterns which direct different types of particles along different surfaces paths, as a means to separate particles based on subtle differences in their character: size, local shape / roughness, near-surface modulus, net charge, and distributions in surface charge. The program combines experiments and simulation to develop application-driven design rules and maximize separation efficiency.The novelty of this program lies in the use of surface patterns and nanotextures to manipulate particles by combined hydrodynamic and surface interactions. The paradigm of continuous particle rolling over a surface for manipulation and separation of particles is a new and powerful idea which exploits a new interfacial mechanism. To date, the mechanism has been modeled in simple treatments but has not been confirmed experimentally. In addition to being scientifically complex, controlled particle rolling is technologically transformative because it facilitates continuous rather than batch-mode processing. Further, the state space approach to describe adhesive behavior in a complex multi-dimensional variable space is highly transformative as an engineering method. The surface force / flow problem is not generally amenable to simplification through dimensionless groups, and the state space approach provides the opportunity to develop simple scaling laws useful for application-driven designs. Broader Impacts: In addition to the transformative methods to study complex dynamic problems at the interface between materials and transport-engineering, the program will transform technologies that demand precise separation and characterization of micron scale objects. Biomedical and pharmaceutical applications will benefit through the ultimate development of portable cell-sorting devices requiring minimal support instrumentation and technician time. The program also has the potential to overhaul strategies for the design of marine-anti fouling coatings through its incorporation of hydrodynamic considerations in materials design.The program supports the continued development of multidisciplinary fundamental coursework at the intersection of materials and engineering. Efforts to maintain diversity and improve the participation by underrepresented and economically disadvantaged groups will be facilitated through participation with several existing organizations and groups at UMass (MRSEC, ICE, NEAGEP), that host recruiting trips and workshops.