Contact Self-Cleaning Mechanics of Repeatable Fibrillar Adhesives

这项拨款的研究目标是阐明天然和合成微米/纳米纤维粘合剂的接触自清洁机理，并设计和展示具有这种自清洁能力的高性能合成弹性纤维粘合剂。当壁虎和甲虫被表面上的微粒污染时，壁虎和甲虫可以通过在清洁的表面上加载、剪切和卸载脚垫的几个循环来清洁它们的脚毛，这称为接触式自洁。这种生物自洁的机制目前还不完全清楚。此外，尽管最近合成的纤维粘合剂在清洁光滑的表面上表现出与生物粘合剂一样高的强度和重复性，但它们在肮脏的表面上的性能会显著下降，因为它们不能去除污垢颗粒。为了实现本项目的研究目标，研究任务包括建立纤维粘合剂自清洁机理的模型，开发具有自清洁能力的高性能弹性体纤维粘合剂的设计方法，以及定向弹性体纤维阵列的制备和表征。所提出的具有接触自清洁能力的仿生纤维抓取材料将使新型商业抓取材料能够在体育、柔性电子、医疗、空间、产品设计、包装和机器人等广泛的现实世界中重复可靠地工作。这项研究的跨学科研究工作将转移到机械工程、机器人和生物工程的许多教育活动中。由首席研究员开发的两门新课程将使用生物启发的粘合剂和微观力学的概念以及本项目中的研究设施和成果，在为期一学期的学生项目中设计和实施新的生物启发材料。

The research objective of this grant is to elucidate contact self-cleaning mechanics of natural and synthetic micro/nano-fibrillar adhesive materials and design and demonstrate high performance synthetic elastomer fibrillar adhesives with such self-cleaning capability. Geckos and beetles can clean their foot-hairs when they are contaminated with particulates on surfaces by several cycles of loading, shearing, and unloading of their footpads on a clean surface, called contact self-cleaning. Such biological self-cleaning mechanics of is not fully understood yet. Moreover, although the recent synthetic fibrillar adhesives have demonstrated high strength and repeatability as good as biological counterparts on clean and smooth surfaces, their performance degrades significantly on dirty surfaces since they cannot shed the dirt particles. To achieve the research objectives of this project, the research tasks include modeling of self-cleaning mechanics of fibrillar adhesives, development of a design method for high performance elastomer fibrillar adhesives with such self-cleaning capability, and fabrication and characterization of directional elastomer fiber arrays.The proposed bio-inspired fibrillar gripping materials with contact self-cleaning capability would enable new commercial gripping materials that could work repeatedly and reliably in broad real-world commercial applications such as sports, flexible electronics, medicine, space, product design, packaging, and robotics. Interdisciplinary research work in this study will be transferred to many educational activities in mechanical engineering, robotics, and bioengineering. Two new courses developed by the principle investigator will use the biologically inspired adhesive and micro-mechanics concepts and research facilities and results in this project to design and implement new bio-inspired materials in student semester-long projects.