Boundary Lubrication and Surface Dynamics

摘要：陀螺、电机和无人航天飞行器等机械系统长期以来需要自润滑材料，这些系统需要长时间免维护运行。对这些材料的更大需求是用于微型和纳米机电系统（MEMS和NEMS）组件，这些组件用于纳米技术的无数应用，包括微波开关和机器人的执行器以及“智能”传感和药物输送设备。在这些应用中，设备的小尺寸增加了它们的表面体积比，增加了由于意外接触运动表面而导致过早机械故障的可能性。要设计一种有效的自润滑材料，润滑剂分子必须具有高的表面迁移率，从而使表面的动摩擦系数低。这一要求必须与已知的趋势相平衡，即吸附底物会减慢分子的运动，从而降低其作为润滑剂的有效性。该研究建议采用实验和理论相结合的方法来提高目前对具有可控分子无序水平的表面涂层的分子迁移率和润滑性能的理解。研究人员建议利用这一认识来开发适用于微纳米机械系统的新型润滑剂涂层。

Abstract 0510239There is a longstanding need for self-lubricating materials for mechanical systems such as gyroscopes, motors, and unmanned space vehicles, in which maintenance-free operation is required over long periods of time. An even greater need exists for these materials for micro- and nano-electro-mechanical systems (MEMS and NEMS) assemblies earmarked for myriad applications in nanotechnology, including actuators for microwave switches and robotics and "intelligent" sensing and drug delivery equipment. In these applications, the miniature scale of the devices increases their surface-to-volume ratio, enhancing the likelihood that premature mechanical failure results from accidental contact of moving surfaces. To design an effective self-lubricated material, it is necessary that lubricant molecules possess high surface mobility, so that the dynamic friction coefficient of the surface is low. This requirement must be balanced against the known tendency of adsorbing substrates to slow down motion of molecules and thereby reduce their effectiveness as lubricants. The research proposed uses a combination of experiment and theory to improve current understanding of molecular mobility and lubrication properties of surface coatings possessing controlled levels of molecular disorder. The investigators propose to exploit this understanding to develop novel lubricant coatings suitable for micro and nano-sized mechanical systems.