RUI: Multiscale Analysis of Adhesion and Friction Coupling Enabled by Bio-Inspired Anisotropic Fibrillar Adhesives

RUI：仿生各向异性纤维粘合剂实现粘合和摩擦耦合的多尺度分析

• 批准号: 2004251
• 负责人: Travis Hu
• 金额: $ 30.41万
• 依托单位: California State L A University Auxiliary Services Inc.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2004251&HistoricalAwards=false
• 关键词: RUI; Multiscale; Analysis; Adhesion; Friction

pNON-TECHNICAL SUMMARYMany organisms in nature have adapted microscopic hairs and fibrils as robust adhesives for locomotion purposes and/or securing a strong attachment. Geckos are among the most studied species for developing bio-inspired dry adhesives due to their fairly large body size and sophisticated toe pad structure. Despite great improvements on adhesion strength, the durability and reusability of many lab-scale 'proof-of-principle' artificial adhesives still lag behind their natural counterparts, even being tested on smoother and cleaner substrates. In this project, adhesive arrays with controlled contact shapes and geometries will be fabricated using template-assisted cast molding and advanced micro-fabrication techniques. Adhesive behavior will be characterized to simultaneously measure adhesion and friction under non-idealized conditions (e.g., on non-dust-free surfaces, and at different temperatures and humidity). Computer simulation will be performed to explain the experimental results. Overall, the proposed work provides an alternative approach to study surface and interfacial phenomena of advanced smart superstructures mimicking nature. Students will examine problems at the crossroads of engineering, materials science, physics, chemistry, and other related disciplines. Exploring a broad range of applications by building up state-of-the-art versatile mechanical system and simulation tools will substantially enhance research productivity, and provide essential research training to undergraduate and graduate students at Cal State LA and in the Southern California region. The educational plan contributes to Cal State LA's long tradition of educating local minority and underrepresented students to become the next generation of engineers, scientists, and educators whose vision is to link science priorities to the solving of societal problems./ppTECHNICAL SUMMARYEfforts to mimic gecko toe pad structure and function seek to develop a new class of advanced adhesives that are not only sticky and easy to unstick, but also non-fouling. Current synthetic dry adhesives suffer from large required preloading and intolerance of dusty environments, which significantly limit their use for sticking to or manipulating fragile and non-dust-free objects. This project focuses on understanding the engaging and disengaging mechanisms of anisotropic fibrillar adhesive units featuring a variety of contact shapes/geometries and structural/materials gradient across multiple lengths and temporal scales. The proposed dry adhesive design incorporates both the geometrical anisotropy seen at the setal level and the special contact shape of the setal branches at the spatula level. The ultimate goal is to elucidate how adhesion and friction are coupled and may be better controlled by rationally designing the geometry dependent dry adhesive units. Adhesive performance will be evaluated under cyclic loadings and non-dust-free environments, as well as different temperatures and relative humidity, using a custom-designed surface force apparatus. Multiscale anisotropic finite-element cohesive-zone modeling will be implemented to parameterize the contact shape dependent interfacial behaviors, and to analyze the adhesive mechanisms, fracture and failures. This project will yield both basic and applied advances in biomimetic research, e.g., development of switchable and self-cleaning surfaces; micro-/nanomanipulations; and high tolerance dry adhesives and drug delivery systems for robotics, energy and biomedical applications./ppThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria./p

PNON技术总结自然界中的许多生物已经将微观的毛发和纤维作为坚固的粘合剂，用于移动和/或确保牢固的附着。壁虎是开发仿生干胶的研究最多的物种之一，因为它们相当大的身体和复杂的脚趾垫结构。尽管粘接强度有了很大提高，但许多实验室规模的“原则证明”人工粘合剂的耐用性和可重用性仍然落后于天然粘合剂，即使在更光滑、更清洁的基板上进行测试也是如此。在这个项目中，将使用模板辅助铸造成型和先进的微制造技术来制造具有可控接触形状和几何形状的粘结剂阵列。粘合行为的特征是同时测量非理想化条件下的粘合和摩擦(例如，在非无尘表面，以及在不同的温度和湿度下)。计算机模拟将被用来解释实验结果。总体而言，这项工作为研究模拟自然的先进智能上层建筑的表面和界面现象提供了一种替代方法。学生将研究工程、材料科学、物理、化学和其他相关学科的十字路口的问题。通过建立最先进的多功能机械系统和模拟工具来探索广泛的应用，将大大提高研究效率，并为加州州立大学洛杉矶分校和南加州地区的本科生和研究生提供基本的研究培训。该教育计划为加州州立大学洛杉矶分校培养当地少数民族和代表性不足的学生成为下一代工程师、科学家和教育工作者的悠久传统做出了贡献，他们的愿景是将科学优先事项与解决社会问题联系起来。/ppTECHNICAL SUMMARYEfforts模仿壁虎脚趾垫的结构和功能寻求开发一种新的高级粘合剂，不仅粘性好，容易松开，而且不会结垢。目前的合成干胶存在所需预加载量大和不耐受粉尘环境的问题，这大大限制了它们在粘在或操纵易碎和非无尘物体上的使用。本项目侧重于了解各向异性纤维粘合剂单元的接合和脱离机制，该粘合剂单元具有各种接触形状/几何以及跨多个长度和时间尺度的结构/材料梯度。建议的干胶粘合剂设计结合了SETAL水平的几何各向异性和SETAL分支在铲水平的特殊接触形状。最终目的是阐明粘合和摩擦是如何耦合的，并通过合理设计依赖于几何形状的干胶单元来更好地控制粘合和摩擦。将使用定制设计的表面力装置，在循环载荷和非无尘环境以及不同的温度和相对湿度下评估粘接性能。采用多尺度各向异性有限元粘结区模型对接触形状相关的界面行为进行参数化，并对粘接机理、断裂和失效进行分析。该项目将在仿生研究方面产生基础和应用方面的进展，例如可切换和自动清洁表面的开发；微/纳米操纵；以及用于机器人、能源和生物医学应用的高耐受性干胶和药物输送系统。/p该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。/p

项目成果

MoO3-x quantum dots-based hydrogel with excellent light-triggered self-healing efficiency and pressure sensitive photoluminescence for accurate remote force measurement

• DOI: 10.1016/j.mtphys.2022.100807
• 发表时间: 2022-08
• 期刊: Materials Today Physics
• 影响因子: 11.5
• 作者: Yiqiang Li;Yuanyuan Mi;Zheyu Liu;Yinping Liu;Weiye Zhang;Shangxing Qiu;M. A. Ramos;Travis Shihao H

Machine learning guided microwave-assisted quantum dot synthesis and an indication of residual H 2 O 2 in human teeth

机器学习引导微波辅助量子点合成以及人类牙齿中残留 H 2 O 2 的指示

• DOI: 10.1039/d2nr03718a
• 发表时间: 2022
• 期刊: Nanoscale
• 影响因子: 6.7
• 作者: Xu, Quan;Tang, Yaoyao;Zhu, Peide;Zhang, Weiye;Zhang, Yuqi;Solis, Oliver Sanchez;Hu, Travis Shihao;Wang, Juncheng
• 通讯作者: Wang, Juncheng

Near-Infrared Responsive Gecko-Inspired Flexible Arm Gripper

• DOI: 10.1016/j.mtphys.2022.100919
• 发表时间: 2022-11
• 期刊: Materials Today Physics
• 影响因子: 11.5
• 作者: Xiaohang Luo;Xiaoxiao Dong;Hong Zhao;Travis Shihao Hu;Xiuping Lan;Lan Ding;Jiapeng Li;Huiqin Ni;Jordan A. Contreras;Hongbo Zeng;Quan Xu

Recent progress of quantum dots for energy storage applications

• DOI: 10.1007/s43979-022-00002-y
• 发表时间: 2022-04
• 期刊: Carbon Neutrality
• 作者: Quan Xu;Yingchun Niu;Jiapeng Li;Ziji Yang;Jiajia Gao;Lan Ding;Huiqin Ni;Peide Zhu;Yinping Liu;Yaoyao Tang;Zhong Lv;Bo Peng;Travis Shihao Hu;Hongjun Zhou;Chunming Xu