Abstract: A MEMS-based novel cell electrofusion chip design was presented for exploring cell electrofusion in a low-voltage condition. Its essence is on the using of microfabrication to shorten the distance between an electrode pair, hence decreasing the required voltage during the alignment and fusion. The chip prototype was fabricated on a SOI substrate, which was subsequently covered by the aluminium film(~2 μm thickness) to enhance the conductivity and SiO₂(150 nm thickness) film to improve the biocompatibility, and packaged via DIP method. On-chip dielectrophoresis-based cell alignment and cell fusion experiments were explored where much smaller voltage(only 1/20 of traditional electrofusion device) was required. Most cells were aligned as cell-cell twins under dielectrophoretic force, which is of significant advantage than multi-cell alignment in traditional method. Tobacco mesophyll protoplasts electrofusion experiments have been explored on the microchip. After load a series of shiort-duration(50 μs) and low-voltage(~40 V) electric pulse, many aligned cells could be fused within several minutes under the high-strength electric field(1—10 kV/cm). It is much faster than traditional method(10—30 min). Compared with PEG(less than 1%) and traditional electrofusion(less than 5%) methods, higher fusion efficiency(about 31%) was also obtained.

Key words: Cell-electrofusion chip, Microelectrode array, Simulation, Dielectrophoresis