Detection of water pathogen based on dielectrophoresis.
Chow, Kun Shyong.
Date of Issue2012
School of Mechanical and Aerospace Engineering
Centre for Mechanics of Micro-Systems
A neutral particle is polarized when it is subjected to non-uniform electric field, and upon polarization, this neutral particle will be moved by dielectrophoretic force. Neutral particles include polystyrene bead, cells, bacteria and other micro-organisms. By utilizing dielectrophoretic phenomena, separation of cells and bacteria can be achieved instantly and this separation method was proven to be effective by previous researchers. Compared to other conventional clinical separation methods, the dielectrophoresis (DEP) separation can greatly reduce the experimental cost and time. On the other hand, water safety has been a critical global issue. More attention has been paid to the safety and cleanliness of drinkable water. Many researchers have also focused on the separation and detection of bacteria in the water medium. Although there are some existing techniques available for cell/bacteria separation currently, those techniques require highly cost and bulky equipments. Moreover, all those techniques require long processing time to separate and concentrate the samples. The objective of this research work is to develop a dielectrophoresis-based device that is able to trap and detect the presence of live bacteria in the water medium and more importantly able to reduce the processing cost and time. The bacteria, such as E. coli and E. faecalis, which can be commonly found in polluted water medium had been selected in this research.