A microfluidic platform with castellated electrodes to separate cancer cells from blood cells

This paper introduces a dielectrophoresis-based platform for the separation of cancer cells from blood cells. The platform consists of a two-layered device: a glass wafer with embedded castellated electrodes and a polydimethylsiloxane (PDMS) channel bonded on top of the glass wafer. The castellated electrodes generate a non-uniform electric field and exert dielectrophoretic force on cells suspended in a low-conductivity medium. The magnitude and direction of the force acting on different cells depend on the applied frequency along with difference in the dielectric properties of each type of cells and the suspension medium. In the experiment, a mixed sample of blood cells and MDA-MB-231 breast cancer cells, both suspended in a low conductive isotonic solution, were injected into the microchannel using a syringe pump. The applied frequency is tuned in such a way that the MDA-MB-231 cancer cells were attracted towards electrode tips whereas the blood cells were repelled away from the electrode tips to achieve successful separation.