Design and numerical analysis of interdigitated radiating-strips electrode for uniform 3D dielectrophoretic patterning of liver cells

This paper presents the design and numerical analysis of a new three-dimensional (3D) electrode having a non-uniform electric field gradient for dielectrophoretic patterning of liver cells. The strength of the dielectrophoresis (DEP) force is influenced by the gradient of electric field generated by the electrode. The new design of the 3D electrode with two different electrode configurations were first modelled and simulated using COMSOL Multiphysics. Results show that the electrical field distribution of vertical configuration concentrated only on the end strips and decays progressively towards the centre while the horizontal configuration shows a more uniform electric field distribution with minimal decrease of the electric field towards the centre. Besides, the horizontal configuration offered 2.7 times higher of the electrical field strength to establish the 3D DEP force hence the 3D cellular pattern. Thus, the electrode with the horizontal configuration has been proposed and optimized to be fabricated for the cell patterning application later on. The optimum electrode dimension identified in this work was 20 µm: 50 µm (gap: height) with a 20 µm electrode width that generates a maximum value of 1.06 × 10⁶ V/m with a voltage set at 5 V. Increasing voltage leads to a stronger electric field and more DEP force would be imposed on the cells. This findings support that the unique design of the 3D electrode can further be used for dielectrophoretic-based patterning mechanism specifically for the complex liver tissue engineering.