Limits to Lubrication Theory in Microsystems

微系统润滑理论的局限性

• 批准号: 0824788
• 负责人: John Tichy
• 金额: $ 25万
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0824788&HistoricalAwards=false
• 关键词: Limits; Lubrication; Theory; Microsystems

Lubrication theory has been one of the most successful and widely used theories in all of engineering and applied science. However, in a wide range of conditions applicable to many researchers in microelectromechanical systems (MEMS), experimental results seem to indicate that forces separating squeezing surfaces vary according to film thickness to the power minus one, rather than minus three, as lubrication theory requires. Hydrodynamic forces arise incidentally, and are usually the largest source of parasitic losses. The motivation of this research is thus to resolve the contradiction between experimental results and theoretical predictions concerning squeeze film dampers. The objective is to develop an improved theory of hydrodynamic lubrication at the microscale. These goals have important implications in the design of MEMS devices. A combined experimental and theoretical/modeling approach will be followed. The damping coefficient will be directly determined as opposed to indirect measurements in the existing MEMS experiments. A theoretical framework for corrections or modifications to lubrication theory will be proposed and tested both by experimental and numerical studies. Employing active MEMS for actuation and sensing in a liquid environment has potential applications in many technologies of industry and medicine. However, the current lack of understanding of lubrication in microscale systems hinders the development of liquid immersed MEMS. There is a real need for developing trusted accurate verified models liquid damping in microscale systems in order to design reliable devices, able to perform as expected. In addition, the PI and co-PI will outreach to K-12 students by building a portable macro scale squeeze film test rig, as dynamically similar to the microscale research device as possible. Bringing theory to life, K-12 students can perform simple experiments and compare their measured effects to the microscale, by visiting the lab, or by web interaction with laboratory results.

润滑理论是所有工程和应用科学中最成功和应用最广泛的理论之一。然而，在适用于许多微机电系统（MEMS）研究人员的广泛条件下，实验结果似乎表明，分离挤压表面的力根据膜厚度的负1次方变化，而不是润滑理论所要求的负3次方。水动力是偶然产生的，通常是寄生损失的最大来源。因此，本研究的动机是为了解决关于挤压膜阻尼器的实验结果与理论预测之间的矛盾。目的是在微观尺度上发展一种改进的流体动力润滑理论。这些目标对MEMS器件的设计具有重要意义。将采用实验和理论/建模相结合的方法。阻尼系数将直接确定，而不是在现有的MEMS实验中间接测量。本文将提出一个修正或修改润滑理论的理论框架，并通过实验和数值研究进行验证。利用有源MEMS在液体环境中进行驱动和传感，在许多工业和医学技术中具有潜在的应用前景。然而，目前缺乏对微尺度系统润滑的理解阻碍了液浸式MEMS的发展。为了设计可靠的设备，能够按预期运行，在微尺度系统中开发可信的、准确的、经过验证的液体阻尼模型是一个真正的需要。此外，PI和co-PI将通过建立便携式宏观尺度挤压薄膜测试装置向K-12学生推广，尽可能在动态上类似于微观尺度研究装置。将理论带入生活，K-12学生可以通过参观实验室或通过网络与实验结果互动，进行简单的实验并将其测量效果与微观尺度进行比较。