Hybrid Acoustic/Electrostatic Levitation Apparatus

The figure schematically illustrates a developmental automated hybrid acoustic/electrostatic apparatus for levitating both electrically charged and electrically neutral liquid drops with sizes up to about 1 mm. The apparatus is particularly suitable for experiments on the growth of protein crystals from solution and on the growth of cells and tissues, all under controlled conditions. In addition to the obvious advantage of levitation for preventing the chemical and thermal contamination that accompanies contact between drops and external objects, this apparatus provides controllable rotation about a horizontal axis (for example, to reduce sedimentation). Moreover, the direction of rotation can be varied to randomize the effective direction of gravitation. Thus, on Earth, the apparatus is expected to provide some of the advantages of low gravitation for suppressing the buoyancy-induced flows that interfere with the growth of high-quality protein crystals and for reducing the adverse effects that gravitation exerts on some cell and tissue cultures.