Using light to move molecules – a novel approach to exploring intermolecular forces

The Atomic Force Microscope uses an ultra fine stylus to 'feel' molecules on a surface as they are scanned underneath it, in much the same way as a gramophone once traced the grooves in a record. We have made the AFM even more sensitive by flashing laser light onto the stylus and causing it to vibrate tiny distances, much smaller than the molecules themselves. By examining the response of the molecules to these vibrations we gain insight into how molecular properties manifest themselves in a wide range of phenomena from adhesion and lubrication, to the folding of proteins and stability of cell membranes. As with all new scientific tools, old questions can be re-examined and new questions asked.