We demonstrate gravity compensation for an ultracold gas of 87 Rb atoms with a time-averaged optical potential. The position of a far-off-resonance beam is temporally modulated with an acoustooptic deflector to efficiently produce a potential with a linear gradient independent of the atomic magnetic sublevels. We realize compensation of the gravity sag and preparation of a degenerate gas in a trap with weak vertical confinement. Optical gravity compensation will provide the opportunity to perform experiments under microgravity in a laboratory and broaden the scope of cold atom research.

The shell body of a 111000 scale car was fabricated by numerically controlled NC machining, integrated circuit compatible processing and micro-electro-discharge processing as an experimental model of a micromachine. The gold-plated nickel body is 30 pm thick, 4.8 mm long, 1.8 mm wide and 1.8 mm high. In the shell body, a 0.7 mm diameter motor is installed. The body powered by the electromagnetic motor runs at the speed of 100 mmJsec. The body and parts are fabricated as a miniature of a full scale model car by those techniques.Those microparts were assembled with a micromanipulator. This demonstration indicates the possibility for complex 3-dimensional machining.