Engineering Research Equipment: A Modified STM/AFM for Complex Fluid Investigations

该提案要求设备升级PI实验室的扫描隧道和原子力微观能力。PI目前拥有纳米级AFM/STM。他建议建造一个密封的房间来容纳仪器，这样可以实现恒温控制，并允许在低真空和清洁气体（如氮气）或固定湿度下进行实验。他还建议将Nanoscope II AFM/STM升级到Nanoscope III；升级后的仪器将允许更大的扫描场，同时仍然保持优异的分子分辨率，并且还将允许测量悬臂尖端的摩擦力和法向力。PI还要求为购买独立于Nanoscope软件的图像分析系统提供资金，该系统将增强图像的视觉检查，并将能够更好地量化结构特征，如周期性。PI主要使用AFM/STM设备对自组装的单层和双层两亲分子在流体-流体和流体-固体界面进行纳米级分辨率的成像。PI在这一领域的研究活动是高质量的，他取得了一些显著的成就，如生物表面活性剂DMPC的波纹相的鉴定。双分子层和单分子层的基本成像研究将有助于更好地理解两亲分子的化学结构与其在自组装中形成的结构之间的关系。这些信息对细胞膜研究和Langmuir-Blodgett膜的技术应用研究具有重要意义。现有设备的升级将大大提高项目研究的质量和可重复性。随着环境控制水平的提高，可以在清洁大气中进行实验，以消除悬臂顶端可能形成的摆桥所产生的毛细力效应。

The proposal requests equipment to upgrade the scanning tunneling and atomic force microscopic capabilities in the PI's laboratory. The PI currently possesses a Nanoscope II AFM/STM. He proposes to construct a sealed chamber to contain the instrument that will allow constant temperature control, and will permit experiments to be undertaken at low vacuum and under a clean gas such as nitrogen or at a fixed humidity. He also proposes to upgrade the Nanoscope II AFM/STM to a Nanoscope III; the upgrade instrument will allow for a larger scanning field while still maintaining excellent molecular resolution, and will also allow for the measurement of frictional forces as well as normal forces at the cantilever tip. The PI also requests funds for the purchase of a image analysis system independent of the Nanoscope software which will enhance the visual inspection of images, and will enable better quantification of structure characteristics such as periodicity. The PI uses the AFM/STM apparatus primarily to image self assembled monolayer and bilayers of amphiphillic molecules at fluid-fluid and fluid-solid interfaces with nanometer scale resolution. The research activity of the PI in this area is of the highest quality, he has produced several notable achievements such as the identification of a ripple phase for the biological surfactant DMPC. The fundamental imaging studies of bilayers and monolayers will lead to a better understanding of the relationship between the chemical structure of an amphophil and the structures it forms in self assembly. This information is of importance in cell membrane research, and in the research on the technological applications of Langmuir-Blodgett films. The upgrade for the existing equipment will significantly improve the quality and reproducability of the PI's studies. With the environmental control upgrade, experiments in clean atmospheres can be undertaken which will remove capillary force effects arising from pendular bridges which can form at the cantilever tip.