Contact: Dr Arthur Graf – [email protected]
Photo induced Force Microscopy (PiFM) is a brand-new technique that provides simultaneously topographic and infrared spectroscopic (IR) mapping of surfaces with a lateral resolution of only 5 nm. Based on the well-known atomic force microscopy (AFM) which uses a sharp tip to map the shape of a surface, PiFM couples an infrared laser with the tip to excite and detect infrared spectra of surface molecules. Infrared spectroscopy is a well-known and powerful technique in materials analysis used to identify molecules and provide information about the bonding between them. However, infrared radiation penetrates many microns into a sample and has a minimum sampling area of > 100 µm2 meaning that the signal averages over large samples sizes. PiFM provides the same information correlated with the shape of the surface with nanometer resolution.
PiFM can be used to map chemical changes across a textile thread, for example that has been exposed to light, or unambiguously identify microscopic flecks of material in a paint surface.
Capabilities: Molecular composition, (qualitative and, in some circumstances, quantitative analysis), chemical mapping on 5 nm scale; correlation of chemistry with topography.
Pros: Non-destructive, surface sensitive, exactly matches bulk infrared spectra and so data can be compared with huge existing libraries.
Cons: Sample size (equipment limited), sensitive to surface contamination.