Control of Mixing Driven by Coalescence of Sessile Drops

该提案将解决固相液滴聚结的问题，例如体积流体性质、接触角和液滴大小的不对称性对两滴在表面上聚结的混合有什么作用，以及当表面是均匀的或非均匀的时可能会发生什么不同的影响。这项工作将使用一个测试平台，在这个平台上，样品滴和试剂滴可以混合。研究计划分为三个目标。首先，pi的目的是研究性质、接触角和尺寸对均匀表面聚结的影响。第二个目标将考虑界面张力不对称，第三个目标将研究更有趣的表面上的聚结，包括超疏水基质。这一建议有一个强有力的、清晰的研究计划，如果成功，将在技术上产生广泛的影响，因为许多应用，如喷涂和喷墨印刷，都依赖于表面上液滴的聚合。在聚结过程中对这些混合模式的控制可以导致利用这种控制的新应用，包括基于中心目标标本滴与含有试剂的几个卫星滴合并的医疗诊断平台。该提案还包括通过开发和教授新的研究生水平课程，监督学生和外展计划对教育产生广泛影响。

This proposal will address issues of sessile droplet coalescence, such as what role does asymmetries in bulk fluid properties, contact angle, and drop size have on mixing in two drops coalescing on a surface, and what different effects could occur when the surfaces are either homogeneous or heterogeneous. The work will use a testing platform, in which specimen drop and satellite drops of reagent are allowed to mix. The research plan is organized into three Objectives. In the first the PIs aim to investigate the effects of properties, contact angle and size on coalescence in homogeneous surfaces. The second objective will consider interfacial tension asymmetry, and the third will examine coalescence in more interesting surfaces, including superhydrophobic substrates.This proposal has a strong, clearly developed research plan that, if successful, can have a technologically broad impact since many applications such as spray coating and inkjet printing rely on the coalescence of drops on surfaces. Control over these mixing patterns during coalescence can lead to new applications that take advantage of this control including medical diagnostic platform based on the merging of a central target specimen drop with several satellite drops containing reagents. The proposal also includes educational broad impact through developing and teaching new graduate-level courses, supervising students, and outreach programs.