Smart surfaces - magnetically switchable light diffraction

By combining specially tailored magnetic stray field landscapes with superparamagnetic plate-like microrods, a tunable reflective diffraction grating was developed in cooperation with the ISC Fraunhofer. 

Depending on their strength and direction, the application of external magnetic fields can either result in a doubling of the grating constant or a complete vanishing of the diffraction effect. The experiments were performed in fluid containers of only a few hundred micrometers height. The obtained results are very promising considering their potential application in smart surfaces with remotely switchable properties.