Mechanics of Miniature Surface Craters for Reversible Adhesion

可逆粘附的微型表面凹坑的力学

• 批准号: 1663551
• 负责人: Nanshu Lu
• 金额: $ 47.96万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1663551&HistoricalAwards=false
• 关键词: Mechanics; Miniature; Surface; Craters; Reversible

This award supports fundamental research on the mechanics of cratered surfaces. Reversible adhesives are designed to form temporary bonds, and ideally can be reusable and capable of strong bonding. Such reversible adhesives can find wide applications in vertical mounting and climbing, releasable wafer and chip handling, as well as reusable bio-integrated electronics. It is well known that reversible adhesion can be achieved through surface interactions such as van der Waals (vdW), capillary, and electrostatic forces as well as volume effects such as suction. Adhesion due to surface interactions has been well studied for gecko-inspired microfibrils with different tip shapes including the concave shape. But the contribution from suction has been widely neglected at microscale. However, manufacturing microfibrils with large aspect ratio can be expensive and time-consuming. If an array of meso-scale craters could provide combined high adhesive strength and reversibility, they may become a practical substitute for microfibrils. The results of this research will guide the design and optimization of cratered surfaces and give a definitive answer to the debate of the suction effect across a broad range of scales. It will also create a pathway for developing a new class of superior adhesives for various applications in engineering and medicine. Building upon the strong track record of previous educational and outreach activities, the PIs will continue to provide research opportunities specifically designed for undergraduate and high-school students from minority institutes through NASCENT REU and women in engineering programs (WEP) at UT Austin.The research objective of this research is to test the hypothesis that arrays of miniature craters on polymer surfaces can lead to significantly improved reversible adhesion with pressure-sensitive strengths. The premise of this research is that cratered surfaces can be tailored for various applications, by choosing proper geometric and mechanical properties, as well as the preloading program. Central to this tailoring is a fundamental multi-scale understanding of the adhesion and decohesion mechanisms. The research team plans to develop a fundamental understanding of reversible adhesion of cratered polymeric surfaces in a broad range of scales through the following three research thrusts: (i) Fabrication of surface craters with sizes ranging from centimeters to micrometers. (ii) Measurements of traction-separation relations and pull-off forces. (iii) Modeling and simulation. The project will be carried out by a synergetic team with complementary expertise in microfabrication, adhesion mechanics, modeling, and simulation.

该奖项支持陨石坑表面力学的基础研究。可逆胶粘剂旨在形成临时粘合，理想情况下可以重复使用并具有很强的粘合能力。这种可逆胶粘剂可广泛应用于垂直安装和爬升、可释放晶片和芯片处理以及可重复使用的生物集成电子设备。众所周知，可逆粘着可以通过表面相互作用(如范德华(VDW)、毛细管、静电力以及体积效应(如吸力))实现。对于具有不同尖端形状(包括凹面形状)的壁虎启发的微纤维，由于表面相互作用而产生的粘附性已经得到了很好的研究。但在微观尺度上，吸力的贡献被广泛忽视。然而，制造大纵横比的微细纤维可能既昂贵又耗时。如果一系列中尺度陨石坑能够提供高粘合强度和可逆性，它们可能成为微纤维的实用替代品。这项研究的结果将指导凹坑表面的设计和优化，并对大范围内吸力效应的争论给出明确的答案。它还将为开发用于工程和医学的各种应用的新型优质粘合剂开辟一条道路。在以往教育和推广活动的良好记录基础上，PI将继续通过新生的REU和得克萨斯大学奥斯汀大学的女性工程项目(WEP)，继续为来自少数族裔学院的本科生和高中生提供专门设计的研究机会。本研究的研究目标是检验这样一种假设，即聚合物表面的微型凹坑阵列可以显著改善具有压敏强度的可逆附着力。这项研究的前提是，通过选择合适的几何和力学特性，以及预加载程序，可以根据不同的应用定制凹坑表面。这种调整的核心是对粘合和解粘机制的基本多尺度理解。该研究小组计划通过以下三项研究努力，在广泛的尺度范围内对有凹坑的聚合物表面的可逆附着力有一个基本的了解：(I)制造尺寸从厘米到微米的表面凹坑。(Ii)牵引力-分离关系和牵引力的测量。(3)建模与仿真。该项目将由一个在微制造、粘合力学、建模和模拟方面具有互补专业知识的协同团队实施。

项目成果

Local and non-local modeling aspects of three-dimensional cracks growth initiation

三维裂纹扩展的局部和非局部建模

• DOI: 10.1007/s10704-020-00424-8
• 发表时间: 2020
• 期刊: International Journal of Fracture
• 影响因子: 2.5
• 作者: Rodin, Gregory J.

Suction effects of crater arrays

火山口阵列的吸力效应

• DOI: 10.1016/j.eml.2019.100496
• 发表时间: 2019
• 期刊: Extreme Mechanics Letters
• 影响因子: 4.7
• 作者: Wang, Liu;Ha, Kyoung-Ho;Qiao, Shutao;Lu, Nanshu
• 通讯作者: Lu, Nanshu

Suction effects in cratered surfaces

凹坑表面的吸力效应

• DOI: 10.1098/rsif.2017.0377
• 发表时间: 2017
• 期刊: Journal of The Royal Society Interface
• 影响因子: 3.9
• 作者: Qiao, Shutao;Wang, Liu;Jeong, Hyoyoung;Rodin, Gregory J.;Lu, Nanshu
• 通讯作者: Lu, Nanshu

Effects of surface tension on the suction forces generated by miniature craters

表面张力对微型陨石坑产生的吸力的影响

• DOI: 10.1016/j.eml.2017.07.004
• 发表时间: 2017
• 期刊: Extreme Mechanics Letters
• 影响因子: 4.7
• 作者: Wang, Liu;Qiao, Shutao;Lu, Nanshu
• 通讯作者: Lu, Nanshu

Mechanics of Crater-Enabled Soft Dry Adhesives: A Review

• DOI: 10.3389/fmech.2020.601510
• 发表时间: 2020-12
• 作者: Liu Wang;Kyoungjin Ha;G. Rodin;K. Liechti;N. Lu