The Atomic Force Microscope (AFM) has been used for the characterization of polydimethylsiloxane (PDMS) surfaces with embedded, randomly dispersed micron-sized glass beads as a model system for a nano-topographical composite material with adjacent hydrophobic/hydrophilic areas. The use of lateral force microscopy (LFM) for the differentiation of regions within a composite material allowed for a mapping of the position of the hydrophilic glass beads, the determination of the height of the protruding beads and the surface area of the glass. Material properties of the PDMS were obtained from AFM contact-mode scans, contact angle measurements and from Fourier transform infrared spectroscopy for both, unexposed surfaces and surfaces exposed for 3 hours with a 185 nm deep UV light source. The UV exposure was found to have an effect on the lateral force signal via a change in the stiffness of the PDMS but the resulting lower contrast was still sufficient for the discrimination of the different regions.