It is widely believed that planets form in accretion discs by the growth of small dust
and ice grains. To verify the scenarios of protoplanetary disc processes including the
transport of material in vertical as well as in radial direction, it is crucial to
understand the interaction of small dust and ice particles with their surroundings,
i.e., with the gas, star light, and other ice and dust particles. In
first laboratory experiments, we observe trapped irregular-shaped water-ice particles
which levitate up to half an hour in a vacuum chamber at a pressure of about 2 mbar due to
photophoresis and thermophoresis. While they are firmly levitating, they rotate
preferentially about their vertical axis. The physics leading to the levitation is
explained and the results of an analysis of the particle rotation are presented.