LEAP-HI/GOALI: Meso-Scale Mechanisms for Friction in Structured Soft Materials: Elastic Hysteresis and Dislocation Arrays

LEAP-HI/GOALI：结构化软材料中的细观摩擦机制：弹性磁滞和位错阵列

基本信息

批准号：
1854572
负责人：
Anand Jagota
金额：
$ 199.86万
依托单位：
Lehigh University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2025-07-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1854572&HistoricalAwards=false
关键词：
LEAP HI GOALI Meso Scale

项目摘要

It is often crucial to control friction of soft material surfaces. For example, high sliding friction between rubber tires and the road surface enables quick braking. In the biological context, it is sometimes desirable to minimize friction, as between a contact lens and the eye. On other occasions high friction is needed, for example when designing hands of a soft robot for grasping objects. This Leading Engineering for America's Prosperity, Health, and Infrastructure (LEAP-HI) Grant Opportunity for Academic Liaison (GOALI) project will develop two novel mechanisms to improve friction of soft materials based on bio-inspired design of near-surface structures. The research will be carried out by a research team with members from Lehigh and Cornell Universities, and Michelin USA, with application to tires. Tire production is a major component of the US industrial profile. Dozens of plants produce over 150 million car, truck, bus and other tires per year. This research will support innovation that is needed to both increase vehicle safety and help the USA to maintain its position as a leading tire manufacturer. Friction as an interfacial property is usually understood to be governed by interfacial intermolecular interactions, coupled to bulk deformation and energy dissipation at macroscopic length scales, for example by viscoelasticity. Recent work on bioinspired and biomimetic materials has shown how appropriately designed near-surface structures at a meso-scale (microns) intermediate between the molecular (nm) and continuum scales (mm and larger) can be used to strongly modulate surface properties like adhesion. This has opened up a new paradigm and mechanisms for design of soft material interfaces, which however has been little exploited for control of friction. Some of these mechanisms are meso-scale versions of molecular level phenomena that underlie the fundamental question of how friction arises between surfaces in the first place. The goal of this project is to study and develop two meso-scale mechanisms underlying frictional energy loss, a) Meso-Scale Dislocation Arrays: in which the interface comprises a periodic array of features that accommodate misorientation by generating meso-scale interfacial dislocations, which can be used to control friction, and b) Elastic Hysteresis: in which periodic near-surface patterning of elastic modulus can be used to set up a periodic resisting force that, in turn, sets up mechanical instabilities and hysteresis to yield large friction enhancement.This 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.

它通常对于控制软材料表面的摩擦至关重要。例如，橡胶轮胎和道路表面之间的高滑动摩擦可快速制动。在生物学背景下，有时希望将摩擦降至最低，因为在隐形眼镜和眼睛之间。在其他情况下，需要高摩擦力，例如，在设计软机器人的手以抓住对象时。这项针对美国繁荣，健康和基础设施（LEAP-HI）学术联络（Goali）项目的领先工程将开发出两种新型机制，以基于生物启发的近场结构设计来改善软材料的摩擦。这项研究将由一名研究团队与Lehigh和Cornell大学以及美国米其林的成员一起进行，并向轮胎应用。轮胎生产是美国工业形象的主要组成部分。每年生产数十种工厂生产超过1.5亿辆汽车，卡车，公共汽车和其他轮胎。这项研究将支持既提高车辆安全性并帮助美国保持领先的轮胎制造商的地位所需的创新。摩擦作为界面特性通常被理解为由界面间相互作用控制，并在宏观长度尺度上耦合到块状变形和能量耗散，例如通过粘弹性。关于生物启发和仿生材料的最新研究表明，如何在分子（NM）和连续体尺度（MM和更大）之间中间的中间体中适当设计的近表面结构，可用于强烈调节表面特性。这为设计软材料界面设计的新范式和机制打开了，但是几乎没有利用用于控制摩擦的机制。其中一些机制是分子水平现象的中级版本，这是首先在表面之间如何在表面之间产生的基本问题。该项目的目的是研究和开发摩擦能量损失的两个中尺度机制，a）中尺度位错阵列：其中界面包含一系列特征，这些特征通过产生中尺度界面位置来适应不良的界面，可以用来控制摩擦，b）弹性滞后：弹性模量的周期性近表面模式可用于建立一个周期性的抵抗力，而周期性抵抗力又设置了机械不稳定性和磁滞以产生大摩擦增强。该奖项反映了NSF的法定使命，并通过使用基金会的知识分子和更广泛的影响审查标准进行评估而被认为值得支持。