text: Improving the resolution and enhancing the instrumentation with user-friendly hardware and software will make AFM/NSOM coupled with IR/Raman a useful characterization tool in many areas including biomedical, materials and life sciences. For example, this technique was used in detecting the spin-cast thin film of poly(dimethylsiloxane) with polystyrene on it by scanning the tip over the sample. The shape and size of polystyrene fragments was detected at a high spatial resolution due to its high absorption at specific resonance frequencies. Other examples include inorganic boron nitride thin films characterization with IR-NSOM. The images of single molecule rhodamine 6G (Rh-6G) was obtained with a spatial resolution of 50 nm. These techniques can be also used in numerous biological related applications including the analysis of plant materials, bone, and single cells. Biological application was demonstrated by detecting details of conformation changes of cholesteryl-oleate caused by FEL irradiation with a spatial resolution below the diffraction limit. Researchers also used Raman/NSOM in tracking the formation of energy-storing polymer polyhydroxybutyrate in bacteria Rhodobacter capsulatus.
  This characterization tool may also help in the kinetic studies on physical and chemical processes at a wide variety of surfaces giving chemical specificity via IR spectroscopy as well as high-resolution imaging via AFM. For example, the study of the hydrogen termination of Si (100) surface was performed by studying the absorbance of Si-O bond to characterize the reaction between silicon surface and atmospheric oxygen. Studies were also conducted where the reactivity of a polymer, a 1000-nm-thick poly-(tert-butylmethacrylate) (PTBMA) combined with a photochemically modified 500-nm-thick poly(methacrylic acid) (PMAA), with water vapor depicted the different absorption bands before and after water uptake by the polymer. Not only the increased swell of PMAA (280 nm) was observed but also the different absorption ability of water was shown by the different transmission of IR light at a much smaller dimension (<500 nm). These results are related to polymer, chemical and biological sensors, and tissue engineering and artificial organ studies. Because of their high spatial resolution, NSOM/AFM-Raman/IR techniques can be used for measuring the width of multilayer films, including layers which are too small (in the x and y directions) to be probed with conventional IR or Raman spectroscopy.