-Abstract- Atomic force microscope (AFM) and IR Spectroscopy have been in combined in a new technology platform (AFM-IR) to map nanoscale chemical, structural and mechanical variations in polymers and other samples. The AFM-IR technique illuminates the sample with light from an infrared laser and measures the absorption of this light on a sub-wavelength scale using the tip of an AFM by detecting local thermal expansion of the sample. AFM-IR can be used both to obtain absorption spectra at arbitrary points and to spatially map IR absorption at selected wavelengths. Simultaneous measurement of the AFM cantilever’s contact resonance frequency as excited by the IR absorption provides a complementary and simultaneous measurement of sample stiffness. These AFM-IR techniques have been used to chemically identify individual chemical components in polymer nanocomposites and multilayer films with spatial resolution as high as 100 nm. Using self-heating AFM cantilever probes we have been able to locally modify the state of a semicrystalline polymer and observe the resulting change in IR absorption spectra on the nanoscale. By changing the polarization of the incident laser source, we have also mapped variations in molecular orientation in individual sub-micron polymer fibers. The presentation will also discuss other AFM-IR applications such as subcellular spectroscopy and chemical imaging on biological cells, including the localization of energy storage polymer granules inside individual bacteria.