Study On Contactless Microarrayer Droplets Control System Based On Machine Vision

Bio-microarray chips are widely used in many fields,such as precise medical treatment,food safety,environmental detection and so on.The main equipment for fabricating bio-microarray chips is the microarrayer.Aiming at the problems of inclination of droplet array and poor stability of droplet morphology by the existing contactless microarrayers,a contactless microarrayer droplets control system based on machine vision is proposed in this paper,which can on-line control the spotting process.The main research contents are as follows:(1)According to the functional requirements of the system,the overall configuration of the microarrayer is planned,and the hardware platform is designed,including the main control module,the droplet eruption control module,the droplet position control module and the droplet monitoring module.(2)The software control system adopts two-tier structure of upper computer and lower computer.The upper PC uses LabVIEW software to design the human-computer interaction interface of the system.The mixed programming of LabVIEW and MATLAB is used to process and recognize the acquired image in MATLAB and monitor the droplet shape.The lower computer STM32 uses Keil MDK ?Vision5 to develop the bottom control program.(3)The image recognition algorithms for monitoring droplet position and shape are studied,including image preprocessing,target segmentation,feature extraction,micro-array droplet tilt monitoring algorithm based on centroid detection and micro-array droplet stability monitoring algorithm based on BP neural network.(4)The prototype of the microarrayer was made,and the related experiments on the control system were carried out.The results show that the prototype can detect the chip which does not meet the standard in the process of fabricating the microarray chip in time,and stop spotting,so as to avoid unnecessary waste of precious biological reagents.The application of machine vision technology in on-line control of sampling process is of great significance for improving the quality and efficiency of mass production of microarray chips and the stability and automation of microarrayer.