Scanning Force Microscope

根据这项建议，要求拨款购买一台扫描力显微镜（AFM，原子力显微镜）。仪器应使用记录材料对比，特别是软样品，以及研究和局部修饰电极表面在溶液中。扫描力显微镜利用显微镜尖端和样品之间的力。尖端位于悬臂的末端，尺寸在微米范围内。这些力引起悬臂梁的偏转，这是通过从悬臂梁背面反射到分裂光电二极管的激光束来测量的。机械驱动器依次扫描尖端到样品的不同位置。在这个过程中，一个控制变量，例如挠度，通过一个电子反馈回路保持恒定。所需要的尖端位置垂直调整的存储值可以转换为假彩色图像。当在每个位置存储完整的力-距离曲线时，该方法的机会显着增强，除了挠度和修饰尖端外，还使用其他测量量来得出样品的局部机械，电学和电化学性能。该仪器将用于研究表面的自组装过程或有机分子。这些层对于生成生物膜的实验模型起着重要作用，可以在生物有机体外明确的条件下研究基本过程。此外，电化学可切换功能层应研究膜的形成过程及其电学和电化学性质。新仪器还将用于了解腐蚀过程中氧化层的形成和电池内部界面的演变。该仪器的多功能功能还将用于表征与层状氧化物材料接触的复杂纳米颗粒的表面，用于催化和能量存储。为此，在成像过程中切换样品的状态非常重要。仪器的尖端不仅可以用作测量探针，还可以用作纳米尺寸范围内局部表面修饰的工具。例如，空心悬臂可用于局部递送用于金属结构电沉积的试剂溶液。另一种方法旨在修改尖端，以获得纳米尺寸的等离子体光发射器，用于局部光谱学。

With this proposal, funds are requested for the acquisition of a scanning force microscope (AFM, atomic force microscope). The instrument shall be used for recording materials contrasts, especially for soft samples as well as for the study and local modification of electrode surfaces in solution. Scanning force microscopy exploits forces between a microscopic tip and the sample. The tip is located at the end of a cantilever with a size in the micrometer range. The forces cause a deflection of the cantilever which is measured by a laser beam reflected from the backside of the cantilever onto a split photodiode. A mechanical actuator scans the tip sequentially to different locations of the sample. During this process, a control variable, e.g., the deflection, is kept constant by an electronic feedback loop. The stored values of the required vertical adjustment of the tip position can be transformed to a false-color image. The opportunities of the method are significantly enhanced, when a complete force-distance curve is stored at each location, other quantities measured besides deflection and modified tip are used that allow conclusion on local mechanical, electrical and electrochemical properties of the sample.The instrument to be acquired will be used to study self-assembly processes or organic molecules at surface. Such layers play an important role for the generation of experimental models of biological membranes, with which essential processes can be studied under well-defined conditions outside biological organisms. Furthermore, electrochemically switchable functional layers shall be studied with respect to film formation processes and their electrical and electrochemical properties. The new instrument will also be used to understand the formation of oxide layers in corrosion processes and the evolution of interphases within batteries. The versatile capabilities of the instrument will also be employed for the characterization of the surfaces of complex nanoparticles in contact with layered oxide materials for catalysis and energy storage. For this purpose, it is important to switch the state of the sample during the imaging process. The tip of the instrument shall not only be used as measurement probe but also as a tool for local surface modification in the nanometer size regime. Hollow cantilevers can for instance be used for the local delivery of reagent solutions for the electrodeposition of metal structures. Another approach aims for the modification of the tips to obtain nanometer-sized plasmonic light emitters for local spectroscopy.