Nanoporous Silicon Membrane Embedded With Dielectrophoresis (DEP) Electrodes for Ultrafiltration Improvement for Artificial Kidney

Ultrafiltration is a vital process for toxin removal in an artificial kidney. However, blood clotting, which usually occurs on the surface of ultrafiltration membrane will cause a decrease in filtration efficacy; hence, reducing the efficiency of the haemofiltration process. In this study, a nanoporous silicon membrane with embedded dielectrophoresis (DEP) electrodes was introduced to reduce red blood cells (RBCs) clotting on the surface of membrane. The RBCs were deviated from the surface of membrane via DEP, to reduce clotting. The size of the nanopores were ranged between 50 nm and 80 nm. The efficiency of DEP embedded ultrafiltration membrane was tested by using polystyrene beads and RBCs. The particles responded to specific frequencies applied; ranging between 100 kHz and 15 MHz. To determine the efficacy of the ultrafiltration process, particle size analysis (PSA) was utilised. The results indicated that particles larger than 80 nm were unable to pass through the nanoporous membranes, whereas smaller particles were free to pass through. Finally, the concentration of the passed through particles between embedded DEP and non-embedded DEP was compared to gauge the separation efficacy of DEP electrodes by using a microplate reader. The concentration values showed that the percentage of albumin, ADH and blood plasma that had passed through were 65.80%, 92.60% and 71.40%, respectively, as compared to 44.38%, 47.04% and 34.08% of those without embedded DEP electrodes. This showed that the performance of ultrafiltration membrane had increased by the implementation of DEP mechanism, which reduced RBCs coagulation on the membrane surface.