Thermally induced movement of micro particles observed on a rough surface: A novel observation and its implications for high throughput analysis and synthesis

It is shown how droplets (20–30 μm) can be made to move by a thermal gradient created by a thermal tip. Materials used were solid at room temperature and were then made liquid by holding the environmental temperature above the melting point. A scanning thermal microscope (SThM) was employed to subject these droplets to a strong temperature gradient. The system was then cooled and the movement of the particle was assessed from a topographic image. It was shown how these materials could be manipulated, moved, mixed together and how their chemical state could be assessed by IR spectroscopy. The possibility of doing this on such a small scale opens up new possibilities for high throughput analysis and synthesis.

Research highlights
► Droplets (20–30 μm) can be made to move by a strong thermal gradient created by a thermal tip.
► Particle movement was assessed from a topographic image with the same thermal tip.
► Materials could be manipulated, moved and mixed together.
► The chemical state of the material could be assessed by photothermal IR spectroscopy.
► New possibilities for high throughput analysis and synthesis.