Design And Development Of A Microjet Impinging System For Cooling And Rewarming In Vitrification Preservation

The application of microjet technology to the vitrification preservation method is an innovative technology proposed in recent years,which can effectively solve the problems of low heat efficiency,low sample load,and high pollution risk of the traditional vitrification preservation method.This technique requires the cooling fluid and rewarming fluid actively sprayed to the sample or the carrier.When applying this technique for vitrification preservation,it is necessary to design and manufacture a microjet impinging device for cooling and rewarming;however,this existing devices exist some drawbacks such as low degree of automation,complicated operation and poor consistency of process control.In response to this situation,this paper combination with the mechatronics engineering principles and technical designs and develops a system for cooling and rewarming in vitrification preservation with automatic functions.The main contents include:(1)Overall scheme design.Analyze the shortcomings of the existing the cooling and rewarming device based on the principle of micro-jet,put forward the development requirements of the new system,analyze what functions are required by the system,and propose the functional modular design first,and then the integrated design from the two aspects of structure and control Program.(2)Detailed design of the functional module.Through the simulation research of AMEsim software,the relationship between air pressure and time is obtained,so as to guide the selection of components and the control of the working substance drive module;the tank design is carried out according to GB150-2011.The manual regulating valve of the self-pressurizing liquid nitrogen tank is converted into the regulating valve controlled by stepper motor,finish automatic control of regulating valve of self-pressurized liquid nitrogen tank.Use comsol simulation to guide the design of alcohol heating module;select fuzzy control algorithm to achieve temperature control of alcohol heating process.Combined with dynamic analysis,understand the stability and movement of the clamping process,complete the design of the automatic clamping module;complete the design of the experimental cavity according to the functional requirements of the experimental cavity.(3)Integrated design of the system.Analyze the structural composition of each functional module,and determine the installation and distribution of these structures from globally,which according to the principles of water-gas-electricity separation and space utilization as high as possible;design the aluminum frame to complete the installation of structural parts,design sealing strip and sealing door to seal the experimental chamber,then finish the system structure integration.The PLC integrated machine is used as the controller,design the control circuit of each functional module,Summarize the detailed circuit diagram of the system and finish the hardware design of the system;Follow the steps of the cooling and rewarming experiment,draw a complete system control flow,then finish the system software design.(4)The system test.Use the built-in cooling and rewarming system to perform functional module tests to evaluate whether each functional module of the system meets the design requirements.A large number of cell-free solution cooling and rewarming experiments were carried out to prove the efficiency,stability and consistency of the microjet cooling and rewarming system designed in this paper.The system has a high degree of automation,stable and reliable system operation,and simple operation,which improves the efficiency of biological material cryopreservation,and has strong practical value.