A Micro EIT Sensor for Real-time and Non-destructive 3-D Cultivated Cell Imaging

A micro electrical impedance tomography (EIT) sensor with radially distributed planar electrodes was designed, characterized, and experimentally validated for real-time and non-destructive 3-D cultivated cell imaging. The 12-mm cylindrical sensor was consisted of 17 circular micro electrodes, including 16 sensing electrodes and a reference electrode. The sensor's characteristics, i.e., dynamic range of measurement and sensitivity, were examined by finite element simulations and actual measurements. MCF-7 breast cancer cells were then cultivated to form the spherical aggregate and 3-D image reconstructions were performed on three solutions containing varying number and locations of cell aggregates. Furthermore, real-time imaging of cell-drug response between a MCF-7 cell aggregate and diluted Triton X-100 solution was carried out and the 3-D conductivity variation associated with this transient process was captured successfully and reconstructed in high accuracy. The simulation, 3-D cell aggregate imaging experiments and real-time reconstructions of cell-drug response suggest that the EIT-based micro sensor has the potential to study non-destructively and in real time the dynamic biological behavior of a 3-D cell culture system.