From micro field cages for living cells to Brownian pumps for submicron particles

The investigation of living cells in microstructures fabricated by semiconductor technology is a new field of research, which has found its first biotechnological and medical uses. This presentation contains selected examples of three-dimensional micro electrode systems designed to handle and characterise adherently growing cells, to determine their adhesion and surface migration and for their cultivation under strong electric fields (up to 50 kV/m). The trapping and the aggregation of cells and submicron particles (e.g. viruses) in multipole field cages are explained. Two new principles, (i) the use of electronic resonances to increase the polarisation forces and (ii) the computer-based investigation of cell rotation and cell dielectrophoresis, are demonstrated. Additionally, some results dealing with the concentration and motion of submicron particles using Brownian pumps are given. Finally, perspectives for such semiconductor micro-devices are outlined