Capture and Release of Droplets Using Advanced Materials for High Technology Applications

液滴对于高科技的微流控及传统的涂层技术都非常重要；而液滴的控制，如在指定位置实现液滴捕获或释放，对于实现这些应用尤为关键。形状记忆材料在液滴控制方面受到了广泛的研究，但也存在一些亟待解决的问题。本项目拟将一种新型的形状记忆材料应用在液滴及润湿性控制领域，针对目前形状记忆材料在液滴控制方面存在的突出问题，提出具体解决方案。具体来说，首先，我们拟发展新型低温形状记忆材料以代替目前广泛研究的高温热致形状记忆材料。其次，我们将发展双向光触发形状记忆材料以实现液滴的可逆捕获/释放。再次，我们将发展一种新的理论模型以理解弹性毛细现象在液滴捕获/释放中的作用机制。最后，在上述理论研究的基础上，我们将基于最新的研究成果发展一种新的基于低温可逆液滴捕获/释放形状记忆材料的防除冰技术。项目的开展将深入揭示液滴捕获/释放的物理机制，为其示范应用奠定理论基础。

This is an exciting research program that provides an opportunity to take shape memory materials (SMM) and apply them in the area of droplet technology and wettability. Droplets are present in many high-tech applications such as microfluidics, and lab-on-a-chip to more traditional areas such as coating. Manipulation of droplets, mainly capture and releasing them in desired locations is of utmost important for such applications. However, there is an urgent need to enhance our understanding of the physics of capture and release of a droplet; this is important to realize the above applications. This proposal aims at answering key scientific questions such as: How to expand the use of shape memory materials to manipulate the wetting, beyond the currently used high temperature thermal-based system? We will find the answer to this question by using special low temperature SMM that then will be used for droplet capture and release applications sated above. Another important question is: How to have a reversable droplet capture and release systems that can function repeatedly for both capture and release? In this direction we will use a two-way SMM that is activated by light. Such a system will overcome the current challenge of cycling through capture and release of a droplet, which is a bottle neck for some of applications stated above. Finally, we will ask, how elasto-capillary phenomenon can be applied to SMM to facilitate development of novel droplet capture and release systems? Specifically, the area of elasto-capillary remains largely unexplored when it comes to understanding of how a droplet, not only can be captured, but also to be released. We propose to develop an analytical model based on surface energetics and bending stiffness of structures in contact with liquid to develop design guidelines for using SMM in the context of elasto-capillary. Development of such a model can lead to insights that leads to breakthrough technologies for droplet manipulation. Answering such questions will lay the foundation for creating new knowledge in the area of droplet capture and release using smart materials. It further advances the field by using the generated basic scientific knowledge to construct a demonstration system that shows how the advancement of science achieved in this proposal can be put to practical use and open the doors for further technologies to be developed in the next phases of this work. In this direction we will develop and test a novel deicing system based on shape memory materials.