We propose fabrication method of a planar quadrupole microelectrode for dielectrophoresis (DEP), which is fabricated by Au thin-film, ion coater and box cutter. This method is more cost effective and simpler than previous existing methods. We conducted two experiments for confirming usefulness of the Au DEP chip. Those are separation of yeast cells and trap force of DEP. To separate yeast cells, we used viable and non-viable cells. DEP force arises when an inhomogeneous AC electric field and sine wave frequency were applied to microelectrode. The Au DEP chip is able to distinguish between viable and non-viable cells and separate them by frequency dependence and the flow with Syringe pump. The chip can obtain viable cells which were trapped without contact to the microelectrode. The viable cells can use for fusion or cell culture. Furthermore, we carried out another experiment to investigate the trap force. The trap force of Negative-DEP becomes gradually weak when the frequency increases with 0.1, 0.5 and 1MHz. We were able to confirm relation between trap force and frequency by the Au DEP chip. The trap force has frequency dependence. Through the two experiments, we have established usefulness of the Au DEP chip.

We propose fabrication method of a planar quadrupole microelectrode for dielectrophoresis (DEP), which is fabricated by Au thin-film, ion coater and box cutter. This method is more cost effective and simpler than previous existing methods. We conducted two experiments for confirming usefulness of the Au DEP chip. Those are separation of yeast cells and trap force of DEP. To separate yeast cells, we used viable and non-viable cells. DEP force arises when an inhomogeneous AC electric field and sine wave frequency were applied to microelectrode. The Au DEP chip is able to distinguish between viable and non-viable cells and separate them by frequency dependence and the flow with Syringe pump. The chip can obtain viable cells which were trapped without contact to the microelectrode. The viable cells can use for fusion or cell culture. Furthermore, we carried out another experiment to investigate the trap force. The trap force of Negative-DEP becomes gradually weak when the frequency increases with 0.1, 0.5 and 1MHz. We were able to confirm relation between trap force and frequency by the Au DEP chip. The trap force has frequency dependence. Through the two experiments, we have established usefulness of the Au DEP chip.

We proposed a simple and low cost dielectrophoretic device to trap and isolate single target cells. The device consisted of a metal coated chemically etched fiber and an AC signal generator. It did not require microfabrication technologies or sophisticated electronics. Using this system, we could easily trap and isolate yeast cells at will. Furthermore, our dielectrophoretic manipulator also could discriminate between live and dead cells by tuning of the applied signal frequency. From these experimental investigations, it was found that our proposed dielectrophoresis tweezers using metal coated chemically etched fiber was a promising tool for the single cell manipulation and isolation.

Dielectrophoresis (DEP) force will arise when an inhomogeneous AC electric field with sinusoidal wave is applied to microelectrodes. By using DEP, we could distinguish between viable and non-viable cells by their movement through a non-uniform electric field. In this paper, we propose a yeast cell separation system, which utilizes an Au DEP chip and an optical tweezers. The Au DEP chip is planar quadrupole microelectrodes, which were fabricated by Au thin-film and a box cutter. This fabrication method is low cost and simpler than previous existing methods. The tip of the optical tweezers was fabricated by dynamic chemical etching in a mixture of hydrogen fluoride and toluene. The optical tweezers has the feature of high manipulation performance. That does not require objective lens for focusing light because the tip of optical tweezers has conical shape. By using both the Au DEP chip and optical tweezers, we could obtain three-dimensional manipulation of specific cells after viability separation.

Dielectrophoresis (DEP) force will arise when an inhomogeneous AC electric field with sinusoidal wave form is applied to micro electrodes. The DEP is able to distinguish between viable and non-viable biological cells by their movement through a non-uniform electric field. The viable cells can be used for analytic chemistry, cell culture or fusion. The aim of this research is yeast cell culture after distinction of viable and nonviable cells on Au thin-film DEP chip. We fabricated a planar double pole electrode for DEP using Au thin-film and a box cutter. This fabrication method is low cost and simpler than the previous existing methods. We observed cell culture under the terms of DEP (1Vpp-5MHz) after distinction between viable and non-viable yeast cells. The Au thin-film DEP chip could obtain viable cells which were trapped at the micro electrodes. The daughter cell became as big as the mature cells after about 50 minutes of observation. In other experiments, we confirmed whether the Au thin-film DEP chip can trap yeast protoplasts or not. When we applied 4Vpp and over 40kHz, the yeast protoplasts were trapped at the micro electrode. This experimental result is very important for performing fusion of cells. We confirmed usefulness and possibility of Au thin-film DEP chip through these experiments.