Micropillar based active microfluidic mixer for the detection of glucose concentration

Active microfluidic mixer has attracted remarkable interest towards the applications in the Lab on Chip (LoC) for fast and accurate fluid mixing. In this work, the standard MEMS processes have been successfully implemented to fabricate the active electromagnetic microfluidic mixer incorporating micropillar on flexible membrane for glucose measurement. Three main parts of the mixer, i.e., a planar electromagnetic coil with permanent magnet, a mechanical movable membrane with pillar and microfluidic channels that were fabricated separately and later bonded with corona discharging process to complete the construction of the microfluidic mixer. The mechanical movable membrane and microfluidic channels are made of polymer and fabricated using soft-lithography technique. Analysis results show that the fabricated microfluidic mixer operated using low electrical current of below 0.5 A produced the mixing index above 0.8 within 4 s. Mixture analysis of fluid samples tested at frequencies of 1.1 kHz, 2.3 kHz and 3.7 kHz shows much better mixing performance as compared to its passive mode condition. The functionality of the fabricated mixer was tested by mixing the DNS reagent and glucose solution. The detection of glucose concentration in the microfluidic mixer chip is indicated by comparing the correlation coefficient R-2 with the conventional method. The evaluation result shows that the R-2 of the mixture produced by the fabricated device shows a comparable value with that of conventional method showing a very promising approach for the diabetic patient diagnosis and food analysis.