Biomimetic Micro/Nano-structured Adhesive Materials with "Smart" Properties

随着机器小型化和性能密度最大化的需求迅速增长，相似和不同材料组件的有效粘附和/或连接已成为制造生物传感器、医疗设备、微电子和许多其他技术的最关键技术先决条件之一，在这些技术中，其他材料连接方式（例如螺栓-螺母、紧固、焊接）无法有效工作。该研究计划旨在开发具有智能性能的仿生微纳米结构粘合材料，用于下一代先进材料和制造工艺。受到生物系统的优越性能和结构的启发，例如莲花超疏水抗粘叶子和壁虎粘趾垫，在当前的发现资助项目中，我的研究团队开发了几代仿生微结构，并使用它们来定制粘附和相关的界面现象，例如材料之间的润湿，变形和开裂界面。我们还开发了各种纳米级材料，并对聚合物粘合剂的粘弹性行为和纳米级表面相互作用有了深入的了解。在先前成功的基础上，拟议的项目将进一步发展这一令人兴奋的仿生领域，通过扩展纳米技术和纳米科学的最新进展，开发具有多功能“智能”特性的新一代仿生粘合剂。基于自己的研究成果和文献报道，我们提出了将功能纳米复合材料用于仿生粘接结构的新概念；导电纳米填料之间的相互作用及其与聚合物基体的相互作用将使纳米复合仿生粘接结构有可能提供多功能的“智能”特性。我们的胶粘剂研究已经在电子制造业中建立了良好的应用环境。我们将重点关注电导率，压电响应和粘附适应等智能。纳米级功能性填充物（例如银）将被加入到仿生结构中，使其具有导电性，从而为粘合材料提供诸如压电和传感特性之类的“智能”功能。这些智能仿生结构将被先进的化学功能化，使其具有适应性粘附在具有挑战性的表面。例如，壁虎能很好地适应干燥和潮湿的环境；但目前的壁虎仿制品缺乏这种适应性，限制了它在潮湿条件下的应用。在该项目中，将合成新型的水凝胶状薄膜，并利用其对粘附结构进行功能化，使其具有所需的适应性粘附性能。与壁虎脚垫上的表面蛋白质类似，表面聚合物凝胶具有响应环境条件变化的能力。此外，本研究将探索如何将已开发的技术和机制理解转化为生物和机械系统应用中有效的粘附和粘合过程。总的来说，拟议的研究项目处于生物纳米材料领域的前沿，并为研究生提供了良好的培训机会。计划中的研究活动具有原创性和创新性，可能导致革命性的进步，对科学界产生广泛的影响。该计划将有助于保持加拿大科学界和制造业的竞争优势，并造福人类。

With the rapidly growing demand to miniaturize machines and maximize their performance density, the effective adhesion and/or joining of similar and dissimilar material components has become one of the most critical technical prerequisites for manufacturing biosensors, medical devices, microelectronics and many other technologies at ever-smaller scales, where other means of materials joining (e.g., bolts-nuts, fastening, welding) do not work effectively. The proposed program of research aims at the development of biomimetic micro and nano-structured adhesive materials with smart properties for next-generation advanced materials and manufacturing processes. Inspired by the superior properties and structures of biological systems, such as lotus superhydrophobic anti-adhesive leaves and gecko adhesive toe pads, in the current Discovery Grant program, my research team has developed several generations of biomimetic micro-structures and used them to tailor adhesion and associated interfacial phenomena, such as wetting, deformation, and cracking at interface between materials. We also developed various nanoscale materials and acquired a deep understanding of viscoelastic behavior of polymer adhesives and nanoscale surface interactions. Building on the previous successes, the proposed program will further develop this exciting biomimetic field by extending recent advances in nanotechnology and nanoscience to develop a new generation of biomimetic adhesives with multifunctional "smart" properties. Based on our own research findings and literature reports, we have developed a new concept of using functional nanocomposite materials in the biomimetic adhesive structures; the interplay among the electrically conductive nanofillers and their interaction with the polymer matrix will make the nanocomposite biomimetic adhesive structures possible to deliver multifunctional “smart” properties. A nice niche of application of our adhesive research in electronic manufactures has been established. We will focus on such smartness as electrical conductivity, piezoelectric responses and adhesion adaptation. Nanoscale functional fillers (e.g. silver) will be incorporated into the biomimetic structures to make them electrically conductive so as to deliver such “smart” functions as piezoelectric and sensing properties to adhesive materials. These smart biomimetic structures will be functionalized with advanced chemistry to make it have adaptable adhesion to challenging surfaces. For example, Geckos are well adapted to both dry and wet conditions; but current gecko mimics lack this adaptability and limits its applications in humid and wet conditions. Under the proposed project, new types of hydrogel-like thin films will be synthesized and utilized to functionalize the adhesive structures so that they can have the desired adaptable adhesion properties. Similar to surface proteins on the gecko foot pad, the surface polymer gel have the ability to response to changes in environmental conditions. Furthermore, this research will explore ways to transfer the developed technology and mechanistic understanding into effective adhesion and bonding processes used in biological and mechanical systems’ applications. Overall, the proposed research program is at the forefront of the field of bionanomaterials and provides excellent training opportunities for graduate students. The planned research activities are original and innovative, likely leading to revolutionary advances that will have a broad impact to the scientific community. This program will help maintain the competitive advantage of Canadian scientific community and manufacturing industries and benefit mankind as well.