Collaborative Research: Control of Contact Friction of Van der Waals Heterostructures

合作研究：范德华异质结构接触摩擦的控制

• 批准号: 2306038
• 负责人: Rosa Espinosa-Marzal
• 金额: $ 35万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2306038&HistoricalAwards=false
• 关键词: Collaborative; Research; Control; Contact; Friction

Two-dimensional materials enable creating a new class of nanoscale material systems by vertical, layer-by-layer stacking, resulting in ‘van der Waals’ heterostructures. This project aims to investigate the structural-mechanical-electronic coupling of van der Waals heterostructures with the ultimate goal of enabling friction control at nanoscale contacts. Created knowledge will advance (1) the design of nano- and microelectromechanical devices serving commercial and U.S. security needs by removing the constraints of high friction as a long-standing hurdle for their functionality, and (2) emerging manufacturing methodologies based on van der Waals assembly. Progress in this field will improve the sustainability and efficiency of manufacturing processes and thus increase U.S. industrial productivity and competitiveness. The collaborative project will train two graduate research assistants. Student demographics at University of California Irvine provide an ideal opportunity for broadening participation in mechanics and nanotechnology and contributing to the education of a diverse STEM work force. The team will take advantage of this opportunity by recruiting students for research engagement at all levels and will provide opportunities for student exchanges between their labs. Findings of this research will be integrated as part of graduate courses at the two universities.It is hypothesized that tuning the structural-mechanical-electronic coupling in ‘van der Waals’ heterostructures will afford control of friction. This is expected because the charge transferred-induced interlayer excitons between the targeted transition metal dichalcogenides monolayers influence the corrugation of the potential energy landscape at the sliding interface. The objective of this hypothesis-driven project is thus to establish experimental and theoretical foundation for van der Waals heterostructures with tunable and controllable friction. The team will investigate (1) how the intrinsic structure (two-dimensional materials combination, stacking order, twist angle, interlayer coupling) of van der Waals heterostructures influences the coupling and friction; and (2) determine how extrinsic factors like strain and electric field effect structural, mechanical and electronic properties of van der Waals heterostructures, and thereby friction. The experimental toolset relies on a scalable approach to assemble van der Waals heterostructures with twist angle control; characterization by photoluminescence/Raman spectroscopy and second harmonic generation; and nanoscale friction measurements correlated with surface topography, adhesion, and stiffness maps. It is also expected that the effect of interlayer charge transfer will make friction less sensitive to oxidation, which will be tested using deliberately oxidized samples.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.

二维材料能够通过垂直、逐层堆叠创建新型纳米级材料系统，从而产生“范德华”异质结构。该项目旨在研究范德华异质结构与结构-机械-电子的耦合。实现纳米级接触摩擦控制的最终目标将通过消除高摩擦的限制来推进（1）满足商业和美国安全需求的纳米和微机电设备的设计。 （2）基于范德瓦尔斯组装的新兴制造方法将提高制造工艺的可持续性和效率，从而提高美国工业生产力和竞争力。该合作项目将培训两个。加州大学欧文分校的研究生研究助理为扩大对力学和纳米技术的参与并为多元化 STEM 劳动力的教育做出贡献提供了理想的机会，该团队将通过招募学生参与研究来利用这一机会。水平并将提供这项研究的结果将作为两所大学研究生课程的一部分。人们再次认识到，调整“范德华”异质结构中的结构-机械-电子耦合将提供对摩擦的控制。这是预料之中的，因为目标过渡金属二硫化物单层之间的电荷转移诱导的层间激子影响滑动界面处势能景观的波纹。因此，这个假设驱动项目的目标是建立实验。具有可调和可控摩擦的范德华异质结构的理论基础该团队将研究（1）范德华异质结构的内在结构（二维材料组合、堆叠顺序、扭曲角度、层间耦合）如何影响耦合和可控。摩擦；(2) 确定应变和电场等外在因素如何影响范德华异质结构的结构、机械和电子特性，从而确定实验工具集依赖于可扩展的方法来组装范德华。具有扭转角控制的德瓦尔斯异质结构；通过光致发光/拉曼光谱和二次谐波生成进行表征；以及与表面形貌、粘附力和刚度图相关的纳米级摩擦测量。还预计层间电荷转移的效应将使摩擦变得不那么敏感。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。