Research On Controlling And Sensing System Of Centrifugal Microfluidic

Microfluidic has emerged as one of new technologies in recent years, it is a subject that combines multiple subjects such as biology, medical and sensing. The most significant feature of the microfluidic is that some complex operations of reagent including preparation, separation, mixing and detection used in biochemical analysis are integrated into one chip of nanoscale and these operations could be completed automatically by the chip. This miniaturized total analysis system (μTAS) not only frees a lot of works from the traditional laboratory but also has played a big roie in biochemical analysis, so it is considered as one of the most promising and practical subject in 21st century.Centrifugal microfluidic is a novel manipulating technology based on the microfluidic, all the structures are integrated into a small disc and the driving force of micro fluid mainly depends on the centrifugal force. The advantage of this approach is that the conventional microfluidic structure driven by external pumps is replaced, which saves costs and simplifies operations. This manipulating approach of micro fluid regulates rotating speed and rotating direction, hence some complicated works could be accomplished. Furthermore, the combination between the configured detection system and the disc is also superior. At some points, the centrifugal microfluidic is closer to μTAS than the traditional microfluidic.The centrifugal microfluidic is on the way to the systematization and platformization in recent years, many mature products based on centrifugal microfluidic have made a huge success on the market, which means the centrifugal microfluidic has a great a prospect and development space. Under this background and requirements, this article built a centrifugal microfluidic platform for controlling and analysis.First the platform offers an extern driver circuit which is for driving external module such as stroboscope, camera and DAQ card. The external driver circuit implemented image capture and regional capture on the disc.A communication circuit was built for communicating with the motor encoder and the sensing nodes, and hence a self-defined protocol was designed for receiving the instruction from the smartphone. A wireless power supply module was designed, hence the sensing node working on the spinning disc can be supplied normally. Moreover, a smartphone client was designed for wireless control and data transmitting, the client is aimed at simplifying and convenient, a lot of functions could be done through a few instructions. On the basis of normal working of the centrifugal platform, two modules of sensing nodes were designed including the paired emitter&detector diodes (PEDD) and the temperature control circuit. The PEDD meshed with the spiral shaped microfluidic disc presented in the article well to calibrate the Bovine Serum Albumin (BSA) concentration from 0 mg/mL to 2mg/mL and the precision is not lower than a spectrophotometer. The temperature control module was completed by a digital discrete PID algorithm and the fluctuation is about 1 degree.Lastly,the hardware interface was opened for the subsequent design.