11. Bioengineering and Bio-thermal Fluid Dynamics

Currently, the technology for high-throughput separation of rare cells from a large number of cells is attracting attention. This technology is very important for applications in ultra-early diagnosis of cancer and regenerative medicine technology using iPS cells. Although various cell separation methods have been proposed in the past, some separation methods inevitably cause mechanical damage or destruction of cells or damage to cell functions due to labeling with fluorescent dyes. Against this background, we have focused on cell separation using dielectrophoresis as a non-invasive separation method that causes little mechanical damage to cells. Dielectrophoresis is a phenomenon in which dielectric particles move along the gradient of an electric field when they are placed in a non-uniform electric field. On the other hand, cell separation devices based on dielectrophoresis technology have several challenges. One of those challenges is Joule heat generated by the strong electric field in the device. That is, cells in the device are exposed to a high-temperature environment caused by the strong electric field. Therefore, there is concern that the heat generated in the cell separation device may affect cell viability. In this study, temperature rise in the proposed device was evaluated numerically and experimentally to disclose the effect of the Joule heat on cells. The thermal structure of the device was investigated by performing the numerical simulation in which the effect of heat generation due to nonuniform electric field was incorporated in the model. In the experiment, micro-LIF method was adopted to measure the temperature in the device. Under the operating conditions of the proposed device, the temperature rise in the device was found to be about 20 degree Celsius and the cell function may be affected depending on the ambient temperature value.