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

0932719 Santor这个项目创建的材料可以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。表面将有选择地粘合和自我清洁，有可能产生颗粒敏感的光学信号。该计划采用了各种粒子(反应胶囊、药物输送载体、细胞、细菌)的模型，大小为0.1×25微米。这些曲面包含各种长度比例的图案，用于设置粒子方向、路径和运动特征(滚动、滑动、跳过、止动)。工程表面将用于微流控方案，基于尺寸、形状、柔软度和表面化学对细胞和其他颗粒进行连续在线分选和分离。智力优势：该计划开发了一种由流体动力和界面作用力组合而成的机制，其中后者独特地由与颗粒相互作用的化学纳米结构和纳米地形特征产生。这些纳米织构赋予选择性(基于局部粒子曲率、柔软度和化学功能)，并控制与表面相遇的流动粒子的运动特征。这些表面的一个重要机制是在纳米结构上发生持续滚动。在这里，具有选择性和可逆结合的动态粘合允许颗粒在表面上连续处理。然后，添加不同表面化学成分(包括一些图案化区域上的纳米结构)或地形的微米级图案，允许不同的颗粒群体在表面上朝着不同的方向移动，这些颗粒群体通过它们的粘附性和与表面的净接触面积来区分。该程序将开发引导不同类型颗粒沿不同表面路径的图案，作为一种基于颗粒特征的细微差异来分离颗粒的方法：尺寸、局部形状/粗糙度、近表面模数、净电荷和表面电荷分布。该程序将实验和模拟相结合，以开发应用程序驱动的设计规则，并最大限度地提高分离效率。该程序的新颖之处在于使用表面图案和纳米结构通过结合流体力学和表面相互作用来操纵颗粒。连续粒子在表面滚动以操纵和分离粒子是一种新的、强有力的概念，它利用了一种新的界面机制。到目前为止，这种机制已经在简单的治疗中建立了模型，但还没有得到实验证实。除了科学上的复杂性，受控颗粒滚动在技术上也是革命性的，因为它促进了连续而不是批量模式的加工。此外，在复杂的多维变量空间中描述粘接行为的状态空间方法作为一种工程方法具有很强的变革性。表面力/流问题一般不能通过无因次群进行简化，而状态空间方法提供了开发适用于应用程序驱动的设计的简单比例律的机会。更广泛的影响：除了研究材料和运输工程之间的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开发，这些设备只需最少的支持、仪器和技术人员的时间。该计划还有可能通过在材料设计中纳入流体力学考虑因素，彻底改变海洋防污涂层的设计策略。该计划支持材料与工程交叉学科的多学科基础课程的持续发展。将通过参加马萨诸塞州大学现有的几个组织和团体(马萨诸塞州经贸委、国际教育、经济和社会理事会、NEAGEP)促进维持多样性和改善任职人数不足和经济处境不利群体的参与，这些组织和团体主办招聘旅行和讲习班。

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.