Honeycomb filter. Coloured scanning electron micrograph of a three-dimensional honeycomb struc- ture made of copper. Structures like this can be used as particle filters for fuel and as filters for far infrared radiation in astronomy. The hexagonal chambers may also store materials needed for other processes. The honeycomb structure was made using LIGA technology. LIGA is a German acro- nym for the phrase Lithographie, Galvanoformung, Abformung". During the LIGA process, X-rays are shone in a pattern onto a substrate. The X-rays alter the properties of the exposed areas so that they can be washed away to leave a microstructure. Magnification: x90 at 6x6cm size."