Adhesive Nano-Structures

《自然》提供了在微米和纳米长度尺度上使用图案来定制特定环境的粘合剂行为的显著例子。一个令人兴奋的例子是，经过一个世纪的研究，壁虎最近才被理解。它的脚上覆盖着一层层次分明的毛发状结构，跨越微米和纳米尺度。最后，数百万个200-500纳米大小的刮刀通过范德华力粘附在光滑和粗糙的表面上，而范德华力仅在几纳米范围内起作用。有趣的是，虽然范德华力提供了分子键合力，但毛发状结构的几何和拓扑结构在决定粘附和脱粘的力学和物理方面起着关键作用。在这些生物学观察的激励下，我们将探索高性能设计工具和纳米制造技术的开发和演示，以实现具有工程粘合性能的纳米结构：粘合特性可以根据个人应用进行定制。该方法将高保真仿真工具与形状和拓扑优化工具相结合，这些工具能够精确地模拟纳米和微尺度的表面力相互作用，从而可以定制粘合剂的性能。最先进的纳米制造技术将被用于实现粘接纳米结构，并将进行一个纳米力学实验项目来验证该方法。我们研究的智力价值是广泛的。它不仅汇集了多种尚未被认为是一致的前沿技术，而且在每一项技术上都取得了进步：粘附、微/纳米结构、设计、高性能计算和纳米制造。这项研究还承诺在科学、工程、生物和医学领域的一系列令人印象深刻的技术领域产生更广泛的影响，而不仅仅是提出的具体任务。这些包括但不限于：促进可靠的纳米制造工艺（如软光刻）的策略；实现从微观到宏观的新型干式胶粘剂；促进生物植入物结合位点纳米制造的设计技术MEMS元件表面工程；以及可用于设计用于细胞捕获、粘附和生长的粘附基质的技术。研究生（以及我们将寻找的本科生）将接触到应用于纳米技术的计算和实验工作的各种前沿技术。从代表性不足的群体和妇女中招收合格学生的具体努力。

Nature provides remarkable examples of the use of patterning on micro and nanometer length scales to tailor adhesive behavior for specific environments. An exciting example that has just recently been understood after a century of inquiry is the gecko. Its feet are covered with a hierarchical hair-like structure that spans micro and nanometer scales. At the end, millions of spatulae, each on the order of 200-500 nm adhere to smooth and rough surfaces through van der Waals forces which operate only over a range of a few nm. Interestingly, while the van der Waals forces provide the molecular bonding forces, the geometry and topology of the hair-like structure plays a key role in determining the mechanics and physics of adhesion and decohesion. Motivated by these biological observations, we will explore the development and demonstration of high-performance design tools and nanofabrication techniques for the realization of nanostructures with engineered adhesive properties: the adhesion characteristics can be tailored to the individual application. This approach is to couple high-fidelity simulation tools capable of accurately modeling nano- and microscale surface force interactions, with shape and topology optimization tools allowing the tailoring of the adhesive properties. State-of-the-art nanofabrication technologies will then be used to realize the adhesive nanostructures, and an experimental nanomechanics program will be undertaken to validate the approach.The intellectual merit of our research is extensive. Not only does it bring together multiple cutting edge technologies that have yet to be thought of in concert, it makes advances in each individual technology: adhesion, micro/nanostructures, design, high-performance computing, and nanofabrication. The research also promises broader impact across an impressive spectrum of technologies in science, engineering, biology, and medicine beyond the specific tasks proposed. These include, but are not limited to: strategies to facilitate reliable nanomanufacturing processes such as soft lithography; the realization of novel dry adhesives for use at micro through macro scales; design technology to facilitate the nanofabrication of bonding sites for biological implants; surface engineering of MEMS components; and technology that can be used to design adhesive substrates for cell capture, adhesion, and growth. The graduate student (and undergraduate student that we will seek) will be exposed to a variety of techniques on the forefront of computational and experimental work as applied to nanotechnology. Specific attempts to recruit from underrepresented groups and women, in seeking qualified students.