Advances in High-Resolution Probes for Scanning Probe Microscopy

This thesis describes work designed to improve the resolution of Scanned Probe Microscopy (SPM). The work falls into three main sections. Sections I and III are both aimed towards making scanned probes with atomic resolution by attaching a single sharp molecule to the end of a tip. Section II is aimed towards making a near-field "optical" probe in the infrared wavelengths. The first section centers on the Touchdown Scheme, a path towards attachment of a single sharp molecule at the end of a conventional atomic force microscope (AFM) tip. The ability to derivatize the tip with a good monolayer was required. Chapters 2 and 3 describe the development and optimization of surface chemistry for this purpose. Included in this development were methods for making chemically patterned surfaces with simple photolithography techniques. Chapter 1 describes mathematical methods to extract intermolecular pair potentials from AFM force measurements. The second section describes a technique for etching infrared-transmitting fibers to very sharp points. These sharpened fibers serve as probes in a Near-field Scanning Infrared Microscope (NSIM). Making tips by chemical etching is far easier than heat-pulling, and the etched probes have a power throughput several orders of magnitude higher than pulled probes. The third section centers on attempts to attach a single molecule to the end of a single carbon nanotube for use as an ultrasharp AFM tip. Bulk derivatization and labeling chemistry of carbon nanotubes was developed and successfully applied to single mounted nanotubes. Along the way, several new methods for handling nanotubes were developed. These include methods for non-oxidative cleaning, making stable suspensions, fluorescence staining, and removal from solution without coalescence.