Miniaturized planar tomography for multiphase stagnant sample detection

Miniaturized device offers portability, high throughput and faster time response compared to macroscale devices. In microdevices, most of the application utilizes planar electrode for microanalysis process as it is inexpensive, highly controllable system and easy for installation. In addition, miniaturized planar sensor offers great potential for microscale medical diagnosis, chemical analysis, environmental analysis, cell culture application and single cell measurement using tomography measurement. In this project, a miniaturized planar tomography system is developed for multiphase sample detection such as liquid-solid and liquid-liquid. Eight-electrode device was fabricated on the copper plated printed circuit board (PCB) using the commercial fabrication technique. The ability of the proposed device in reconstructing images of a multiphase sample using Linear Back Projection algorithm is tested. Experimental results show that the reconstructed images closely resemble with the cross-section of the stagnant multiphase sample

Desktop tomography system using planar ECT device

Miniaturized planar electrical capacitance tomography (ECT) device is fabricated using microfabrication method to accommodate eight planar electrodes to carry out electrical capacitance measurement using tomography technique. Fluids within the detection chamber are detected by the difference of the permittivity parameters. Stagnant and hydrodynamic multiphase samples such as liquid-gas and liquid-liquid are tested. The eight-electrode planar array is fabricated on the copper plated printed circuit board (PCB) and the chamber is fabricated using polymer poly(dimethyl-siloxane) (PDMS). The images of the multiphase sample are reconstructing using Linear Back Projection algorithm (LBP). Computer interface software is developed to display the images of the fluid online. Experimental results show that the reconstructed images closely resemble with the composition of the multiphase sample within the detection chamber

Single cell imaging using electrical impedance tomography

Electrical impedance spectroscopy is a non-invasive technology for characterizing the dielectric properties of biological tissues and cells. Electrical impedance tomography extends impedance measurements from one dimension to two or three dimensions. Impedance measurements are performed across multiple electrodes, mapping the conductivity distribution within an object. In this paper, electrical impedance tomography is used to image a multi-nucleated cell, Physarum polycephalum, growing on agar gel in a miniaturized chip containing a circular 16-electrode array. An impedance analyzer combined with a USB-controlled multiplexing circuit board is used to perform adjacent impedance measurements. An open source software, EIDORS is used for image reconstruction and the system is evaluated using finite element modeling. Experimentally, a preliminary reconstructed image of Physarum is shown. The system has the potential to monitor kinetics of cells culture