Micro Scale Electrical Impedance Tomography Sensor for Dynamic Cell Imaging

Dynamic imaging of flowing cells, especially for flow cytometry, is of great significance for the research in medicine and biology. Compared to traditional optical imaging methods, electrical impedance tomography (EIT) has the advantages of label-free and low cost. It can determine not only the shape and size of cells but also the distribution of its electric properties that cannot be obtained by other methods, presenting a significant advance in the traditional impedance-based detection method. However, the scale of traditional EIT sensor limits single-cell EIT imaging, which is usually around or larger than 1 mm, but the size of most cells is around 10 µm. Therefore, a micro scale sensor for dynamic imaging is designed and fabricated on Printed Circuit Board (PCB), with eight equally-spaced electrodes surrounding a microchannel of 150 µm in diameter. To verify the performance of the micro scale EIT sensor, static sensors with a similar structure were designed and used to reconstruct the grits located in the imaging area, with the shape and position of the grit well reconstructed. Thereafter in experiment, the dynamic sensor was used to image the flowing SMG-C6 cells, and the reconstructed image is similar to the microscopic observations, providing the basis for future EIT -based cell identification, classification, and enumeration.