CAREER: Engineering Surface Interactions to Modulate a Confined Fluid

这个学院早期发展（CAREER）项目的研究目标是利用界面现象来实现纳米尺度上润湿和粘附特性的外部、可逆和局部控制。通过空间（图案）或动态（外部刺激）调制表面来创建表面器件元件的策略在基础实验中得到了发展和探索。为了实现该计划的目标，表面力装置（SFA）将被用作与图案、表面化学和外部场相一致的试验台。所提议的工作的具体目标是：(1)表征在技术相关条件下具有交替润湿特性条纹的表面上液体桥的形成和稳定性；(2)通过改变构象和改变润湿性来创建响应电刺激的表面膜。CAREER教育计划旨在通过给予学生积极制作科学材料的机会，培养他们对科学的真正热情。在开发的课程作业中，这采取了传统的“看一个，做一个，教一个”框架的形式，同时利用维基百科（www.wikipedia.org）的力量和无所不在来利用学生的努力。在实验室里，本科生被鼓励在小组内外展示他们的发现。最后，与全国盲人联合会（NFB）合作，在实验室为NFB青年大满贯的视障学生创建了讲习班。拟议的研究有望产生重大的科学和技术影响。由于反应时间快，体积小，并行操作，微流控装置有可能彻底改变生物和化学分析。除了微流控应用之外，光流控领域作为MEMS、微流控和光学的结合正在兴起。然而，为了使光流体器件充分发挥其技术潜力，需要创造和实施能够在受限流体环境中在纳米尺度上操作的新的控制和驱动手段。控制纳米通道中的流体必须解决的关键问题是流体的驱动和控制、控制局部折射率的方法以及引入机械部件。该项目将测试基于操纵表面相互作用的新策略，以控制纳米级的光学特性和驱动机械部件。拟议的工作将解决与特定设备设计特别相关的基本问题，但预计将影响这一不断增长的领域。

The research objective of this Faculty Early Development (CAREER) program is to harness interfacial phenomena to achieve external, reversible, and local control of wetting and adhesion properties at the nanoscale. Strategies to create surface device elements by modulating a surface spatially (patterning) or dynamically (external stimulus) are developed and explored in fundamental experiments. To achieve the goals of this program, the surface force apparatus (SFA) will be employed as a testbed in concert with patterning, surface chemistry, and external fields. Specific aims of the proposed work are to (1) characterize the formation and stability of liquid bridges on surfaces patterned with stripes of alternating wetting properties in technologically relevant conditions and (2) create surface films that respond to electrical stimuli by changing conformation and altering wettability. The CAREER educational plan is designed to foster a true passion for science in students by giving them opportunities to actively produce scientific material. In the coursework developed, this takes the form of the traditional "see one, do one, teach one" framework, while exploiting the power and omnipresence of Wikipedia (www.wikipedia.org) to leverage students' efforts. In the lab, undergraduates are encouraged to present their findings within the group and externally. Finally, in cooperation with the National Federation of the Blind (NFB), workshops were created in the lab for visually impaired students for the NFB Youth Slam. The proposed research promises to have significant scientific and technological impact. Microfluidic devices have the potential to revolutionalize biological and chemical analysis due to fast reaction times, small volumes, and parallel operations. In addition to microfluidics applications, the area of optofluidics is emerging as a combination of MEMS, microfluidics and optics. To enable optofluidic devices to reach their full technological potential, however, the creation and implementation of new means of control and actuation that can operate at the nanoscale in confined fluid environments are needed. Key areas that must be addressed to control fluid in nanochannels are the actuation and control of flow, the means to manipulate the local refractive index, and the introduction of mechanical components. This program will test new strategies based on manipulating surface interactions to both control the optical properties and actuate mechanical components at the nanoscale. The proposed work will address fundamental issues particularly pertinent in the design of specific devices, but anticipated to affect this growing field at large.