SGER: Feasibility Study of Novel Instrumentation With nN Force Resolution

NN力分辨率新型仪器可行性研究NSF SGER提交给Jorn Larsen-Bass博士的建议由UIUC机械与工业工程系Andreas A.Polycarpou提交许多经历接触的设备，尤其是微/纳米设备的表面特性和界面现象，如粘合、摩擦和磨损，其性能和耐用性受到很大影响。先进的工程系统和微型系统，如磁存储中的磁头磁盘接口(HDI)和微电子机械系统(MEMS)，在摩擦、粘着和纳米机械性能方面的研究取得了很大进展。随着微型系统尺寸的进一步缩小，对系统的公差提出了更高的要求，表面变得更光滑，薄膜变得更薄，可能会出现分子间粘附力强、粘附力高和界面灾难性破坏等现象。尽管其中许多问题已经得到缓解或解决，但本研究中仍然存在并将解决的一个主要问题是分辨率极低的直接测力。拟议的为期一年的探索性研究涉及共同开发和购买能够以非常高的1nN分辨率进行直接测力的新型仪器。目前最先进的直接力仪器能够达到0.5nN-1 nN的力分辨率。力分辨率的3个数量级的提高将通过以下方式实现：(A)将当前系统的质量从200 mg以上大幅减少到20 mg(使用集成电路-IC和MEMS技术的组合)。(B)在力传感器中加入主动振动消除。(C)改进力传感器和执行器的驱动电子设备，以最大限度地减少热漂移。然后，建议的仪器将与现有的多模原子力显微镜(AFM)集成，并将用于执行初步的界面纳米级实验，以演示NN力的分辨能力。具体地说，将进行两种类型的实验：(A)亚纳米压痕--提取亚10 nm超薄层的材料特性的实验，以及(B)使用微系统的所有表面和实际表面(例如，来自磁存储的低漂浮磁头-磁盘接口)进行的附着力和拉脱力实验。这项研究的意义在于，它将使新型直接力测量仪器具有神经网络和可能的亚神经网络分辨率的可行性，并能够在小范围内进行定性的纳米压痕和附着力实验，这是以前不可能实现的。由于新型低质量直接力传感器样机的存在，本研究具有探索性和高风险性。这项研究的成功将对纳米测试和纳米摩擦学的未来产生重大影响。PI在宏观摩擦学方面的背景，以及他应用微/纳米技术在多个长度尺度上解释现象的方法，他强大的仪器背景，以及他与新型传感器制造商和工业公司的密切关系，使他在开发能够分辨NN力并研究亚纳米厚层的界面现象和机械性能的新型仪器方面处于独特的地位。

Feasibility Study of Novel Instrumentation with nN Force ResolutionNSF SGER Proposal submitted to Dr. Jorn Larsen-BasseBy Andreas A. Polycarpou, Department of Mechanical and Industrial Engineering, UIUC The performance and durability of many devices that experience contact, especially micro/nanodevices is heavily influenced by the surface properties and interfacial phenomena like adhesion,friction and wear. Research in the areas of friction, adhesion and nanomechanical properties of advanced engineering systems and miniature systems, such as the Head Disk Interface (HDI) in magnetic storage and microelectromechanical systems (MEMS), have advanced considerably. As the size scale of miniature systems shrinks further, finer tolerances are required, surfaces become smoother, thin-films become thinner and phenomena like strong intermolecular adhesion forces, high stiction and catastrophic failures at the interfaces may occur. Even though many of these problems have been alleviated or resolved, a major issue that remains and will be tackled in this research is the direct force measurementwith extremely low resolution. The proposed one year exploratory research deals with the co-development and purchase of novel instrumentation capable for direct force measurements with very high resolution of 1 nN. Current state of the art direct force instruments are capable of 0.5 nN - 1 nN force resolution. The 3 orders of magnitude improvement in the force resolution will be accomplish by:(a) Significantly reducing the mass of the current systems from over 200 mg to 20 mg (using a combination of integrated circuit-IC and MEMS technologies).(b) Incorporating active vibration cancellation inside the force transducer.(c) Improving the drive electronics of the force transducer and actuator to minimize thermal drift. The proposed instrumentation will then be integrated with an existing multi-mode Atomic Force Microscope (AFM) and will be used to perform preliminary interfacial nanoscale experiments to demonstrate the nN force resolution capabilities. Specifically, two types of experiments will be performed: (a) iasub nanoindentationl-A experiments for extracting material properties of sub 10 nm ultra thin layers and (b) adhesion and pull-off force experiments using isidealln surfaces and actual surfaces from microsystems, e.g., low flying head-disk interfaces from magnetic storage. The significance of this research is that it will enable the feasibility of novel direct force measurement instrumentation capable of nN and possibly sub nN resolution and the capability of performing qualitative nanoindentation and adhesion experiments at small scales that were not possible before. The proposed research is exploratory and high risk due to the novel prototype low mass direct force transducers. The success of this research will have a great impact on the future of nanoscale testing and nanotribology. The PI's background in macrotribology and his approach of applying micro/nano techniques to explain phenomena at multiple length scales, his strong instrumentation background and his strong relation with novel sensor manufacturers, and industrial companies place him in a unique position to develop novel instrumentation capable of nN force resolution and investigate interfacial phenomena and mechanical properties of sub-nm thick layers.