Development of a prototype micro-EIT system using three sets of 15×8 array electrodes

We developed a new microscopic electrical impedance tomography (micro-EIT) system to visualize admittivity distributions within a miniature hexahedral container, where we place small biological samples with a background solution or gel. Each of two facing sides (left and right) of the container is fully covered by a solid metal electrode. We inject current between them, thereby producing a uniform parallel current flow along the longitudinal direction inside the container. Each of three sides at the bottom, front and back is equipped with a 15×8 array of voltage-sensing electrodes. Switching modules are located underneath the container so that we can measure voltage between any neighbouring pair of electrodes. Three switching modules are connected to a 16-channel multi-frequency EIT system to collect induced voltage data from the three sets of 15×8 array electrodes subject to the single fixed current injection. Voltage data set from 360 voltage-sensing electrodes on three sides are utilized to produce cross-sectional images of the admittivity distribution. We describe the design and construction of the new micro-EIT system. Our future work should include development of a customized image reconstruction algorithm for the micro-EIT system and experimental validation.