Optimal fuzzy sliding-mode control for bio-microfluidic manipulation

In biometric and biomedical applications, a special transporting mechanism must be designed for the micro total analysis system (μTAS) to move samples and reagents through the microchannels that connect the unit procedure components in the system. An important issue for this miniaturization and integration is the microfluid management technique, i.e., microfluid transportation, metering, and mixing. In view of this, an optimal fuzzy sliding-mode control (OFSMC) based on the 8051 microprocessor is designed and a complete microfluidic manipulated biochip system is implemented in this study, with a pneumatic pumping actuator, two feedback-signal photodiodes and flowmeters for better microfluidic management. This new technique successfully improved the efficiency of biochemical reaction by increasing the effective collision into the probe molecules as the target molecules flow back and forth. The new technique was used in DNA extraction. When the number of Escherichia coli cells was 2×10²-10⁴ in 25 μl of whole blood, the extraction efficiency of immobilized beads with solution flowing back and forth was 600-fold larger than that of free beads.