Design Of Fully Automated Liquid Processing Workstation Based On Nucleic Acid Extraction

With the development of rapid disease detection,gene sequencing,nucleic acid extraction,biopharmacy and other fields,people need to deal with a large number of biological samples in a short period of time.The traditional manual treatment methods have been difficult to meet the requirements of the market.The automatic liquid processing workstation can not only replace the repeated heavy operation,but also reduce the labor of the operators to a great extent,but also reduce the influence of human error on the experiment.Based on the research of micro liquid treatment technology and the demand of modern liquid treatment,an automatic liquid processing workstation for nucleic acid extraction is designed in this paper.the workstation is mainly composed of worktable and micro liquid transfer manipulator.The manipulator and the mixer are composed of four parts,and the liquid treatment operation is completed by the control system.The manipulator of the workstation adopts a three-dimensional motion mechanism with double right-angle coordinates,which is equipped with a micro-liquid transfer module and a clamping transfer module,in which the micro-liquid transfer module is an injection micro-pump designed by air replacement liquid transfer technology.In order to improve the efficiency of liquid treatment,the pump is designed with eight channels and a single channel.And the transfer mechanism arm is mainly composed of an electric finger,and the transfer between the reagent box and the mixing instrument can be easily completed under the cooperation of the three-dimensional motion structure.The finite element static stress analysis and the modal analysis of the three-dimensional motion structure are carried out by the Workbench of the finite element software Anasys,and the problems existing in the design are further optimized.In addition to the precise liquid-moving operation of the sample,the workstation also needs to meet the functional requirements of mixing,vibration,heating and heat preservation of the sample during the test,so that the small-size well-mixing instrument is integrated in the work station.in addition,to monitor The possible abnormal phenomena in the process of controlling liquid transfer make the test carry out accurate liquid transfer,and a real-time pressure monitoring system and a capacitive liquid level detection system are established.The blockage canbe effectively distinguished by monitoring the internal pressure of the piston in real time.Abnormal states such as bubbles and leakage improve the reliability of the experiment.In order to detect the liquid transfer effect of the workstation,the liquid transfer accuracy of the designed micropump is measured by weighing method.The test results show that the allowable error and the measurement repeatability of the micro-pump are in accordance with the requirements of JJG 646-2006.