4. Conclusion
In this study, we developed a new centrifugal microfluidic system capable of accomplishing fully automated serial dilutions, by utilizing ferrowax microvalves. Using the centrifugal microfluidic system, we successfully achieved six consecutive two-fold and ten-fold dilutions for the crystal violet solution and the Escherichia coli O157:H7 sample, respectively, in a very accurate and loss-free manner. Very importantly, this system was fully automated by taking advantage of the automated actuation of the ferrowax microvalves such that any handling step was not required after the initial loading of the analyte. Moreover, the overall process was completed very rapidly within five minutes due to the elegantly designed minimized procedures. We believe that the fully automated system developed herein has a great potential for the development of diverse point-of-care diagnostic systems involving the serial dilution process.