Grant: Research Tools and Instruments - Category 1 (<$150,000)

The request for an upgrade to the existing 10 year old AFM will replace an aging instrument that is no-longer supported and quickly losing ground to the newer more stable and user friendly equipment. The upgrade will allow for more reliable imaging of difficult sensitive samples using magnetically driven tapping mode (known as MAC mode) with the added ability of being able to direct the tip to the area of interest on the sample. This video access was not available 10 years ago, and has been one of the limitations that has led to the decline in the use of the AFM. We have successfully used MAC Mode to characterize Pt and Pt-alloy nanoparticles on a carbon support, illustrating the ability of this method to characterize difficult samples. That said, the new model will enable even more delicate samples to be investigated, specifically modified electrode surfaces containing DNA or adsorbed liposomes. Our attempts to image these surfaces with our current instrument have been less reliable. Performing these measurements in liquid or in electrochemical environments is also quite limiting. The requested instrument is a newer design which has solved a number of the alignment and sealing issues and will significantly enhance our ability to perform these measurements in liquid. Other users of this instrument are from Chemistry and AMPEL whom are interested in investigating the characteristics of self-assembled structures of macrocycles used to create supra-molecular structures. These structures have been observed using TEM, but after significant sample processing. This new instrument will enable visualization of these structures with little sample pretreatment. Another project involves the use of polymer beads as an assembly motif. These soft beads are difficult to image and the soft imaging capability of this new AFM will readily enhance the characterization of these assemblies which are to be used for the next generation of supercapacitors. At present, the current AFM is used by only a few graduate students, but we predict a large increase in users with the upgrade and enhanced usefulness of the instrument. The AFM will be housed in a building that has a multi-disciplinary approach to materials. We have successfully managed the current AFM for the past ten years which has been used to characterize electrochemical surfaces, polymer surfaces, electrocatalytic systems, fibers, and electrodeposited films.