ECR Seminar / Webinar - By Mr Ted Ahn

Infrared (IR) spectroscopy is a powerful analysis technique for the identification of chemical species based on characteristic absorption of infrared light associated with molecular functional groups. However, the spatial resolution of traditional IR spectroscopy is limited to ~5 μm due to the wavelength of infrared light. In addition, traditional absorption or transmittance experiments are not well suited to materials containing a high percentage of water.

In order to overcome the spatial resolution issue, a new method of generating an infrared spectrum is developed. The sample is exposed to an infrared laser scanned over the wavelengths of interest and the thermal expansion of the material is measured. Two instruments have been commercialized using either an atomic force microscopy (AFM-IR) or a green laser light (mIRage), to measure the thermal expansion.

AFM-IR can simultaneously detect an infrared signal with a high spatial resolution (as small as 10 nm) coupled with surface topographical and force information. The mIRage microscope has a larger maximum resolution (< 1 um) but provides much faster data acquisition and removes the requirement to successfully track the surface with an AFM tip. In this talk, the physical principles and basic operation of the AFM-IR and mIRage will be explained. Examples of polymeric and biological materials will be presented to showcase the capabilities of both instruments.