To enable optical imaging beyond the diffraction limit nearfield imaging techniques such as atomic force microscopy infrared-spectroscopy (AFM-IR) are employed. AFM-IR, specifically, is a hybrid technique, combining atomic force microscopy and infrared spectroscopy. The working principle of AFM-IR is as follows: a pulsed, tunable IR source causes local, short-lived sample heating upon absorption of infrared light (photo-thermal excitation). This heating leads to local thermal expansion which is detected using a sharp atomic force microscope probe with a ~10-20 nm tip diameter. As first demonstrated by Dazzi et. al. the transient thermal expansion of the sample results in a damped oscillatory motion of the cantilever (ring down) with amplitudes that are proportional to the sample absorption coefficient. Thus AFM-IR pro-vides absorbance infrared spectra that resemble conventional FT-IR spectra. The indirect detection scheme of AFM-IR enables not only measurements in air but also of samples in strongly absorbing media, such as water. This bears a huge potential for characterizing biological systems such as proteins, microorganisms and cells in their native state. The first AFM-IR measurement obtained in water by Mayet et. al., was taking advantage of the total internal reflection of the bottom illumination configuration to reduce water absorption. Jin et.al. then later demonstrated measurements on Ge prims with poly (methyl methacrylate) samples of very thin thicknesses (~50 nm).