Research On Key Technologies Of Small-scale High-throughput Bioreactor Experimental Platform

With the continuous advancement and innovation of life science and technology,traditional bioreactor systems are no longer able to meet the ever-increasing variety of requirements,and the bioreactor systems are gradually developing toward high throughput,high efficiency,automation,and low cost.The high-throughput miniaturized reactor experimental platform is a hotspot in current development.In response to the demand for solution agitation in the reactor of the small-scale high-throughput bioreactor experimental platform,a three-eccentric shaft rocking bed was designed and developed.The brushless DC motor was the power of the rocking bed,and the STM32 series MCU was used as the control core.Finally,the rotational speed of the rocking bed was controlled based on the PID control algorithm.The control effect basically met the demand of control precision.In addition,the reactor temperature control structure scheme and system were analyzed and designed and the PT100 was used as the temperature sensor.The temperature control module,the solid state relay,and heating sheet were used to control the temperature.The results showed that the temperature control effect was good and satisfied the requirements of precision.In the aspect of dissolved oxygen detection,the oxygen sensor based on the fluorescence quenching principle was selected.A luminescent light source was designed.The Si-APD was used as the fluorescence sensor and the signal amplifying circuit and the low ripple power were designed.The amplified electrical signal was filtered and the dissolved oxygen detection system was set up.Finally,the experimental results showed that it is feasible.Besides,a method for detecting dissolved oxygen based on light-to-frequency conversion was proposed,and the fluorescence intensity was converted to a square wave signal with a certain frequency.The linear relationship between the frequency value of square wave and the concentration of dissolved oxygen was deduced,and the feasibility of the method was proved theoretically.The experimental platform should have the function of visualizing and storing all kinds of collected data.Based on the MATLAB R2016a environment,the upper computer system software was developed,which communicated with the lower machine through the RS485 interface and the USB serial port respectively,and the communication protocol was the standard MODBUS RTU protocol.The software interface can display all parameters and dynamic curves of the bioreactor experimental platform in real time,and can control the parameters such as speed and temperature of the shaking table.Creating a txt file to store data in real time,and when opening the software,the system time was used as the filename,and facilitated subsequent data analysis.Besides,two problems of Caton and memory overflow were solved.The upper computer system had reserved data interface for future research and development,and had accumulated a certain technological foundation.