Physical Modeling And Experimental Study Of Needle-free Injection And High-precision Micro-injection System

With continuously develop of modern biological medicinal technology, people bring forward higher requirements for drug delivery methods and effect. Compared with traditional transdermal drug delivery system, transdermal drug delivery has obvious advantages and has become a focus of study on drug delivery. In order to break through the skin barrier for drug release, the researchers developed the needle-free injection technology and microneedle technology, and access to the clinical application.In this paper, further studies were carried out on needle-free injection technology and microneedle technology. The content was divided into two independent parts. In the first part, a needle-free injection system powered by electromagnetic force was investigated, the current system had features such as simple structure, double direction movement, and controllable driving force, and overcame disadvantages of the common needle-free injection system. The second part built a micro-injection system based microneedle array, and the injection mechanism was studied, the present work had laid the foundation of the product development of the micro-injection system.The thesis is divided into6chapters. The main contents in each chapter are as follows:Chapter1described the background and significance of the research, the research situation and development trend of the two drug delivery systems were introduced in detailed, and the main research contents are presentedChapter2introduced design principles of electromagnetic force actuator, and the mechanical structure of needle-free injection system was design. At last, control circuit of the needle-free injection system was design by concerning requirements for actuator and analysis of the injection process.In Chapter3, a theoretical model was established to evaluate the injection pressure under system conditions (nozzle diameter, ampoule dimension, voice-coil discharging voltage, etc.). An experimental system was set up to measure the injection pressure dynamically. The experimental results match the predicted values given by the theoretical model. Finally, in-vitro injections using the current needle-free system were carried out with needle injections as control.In Chapter4, a micro-injection system model based micro-pump and microneedle array was established, liquid diffusion model was established by researching the injection mechanism on the soft solid material, the model was able to calculate the time-varying expansion radius.Chapter5built the micro-injection system, control circuit of the system was designed by control theory of micro-pump, and performance test had been made. Finally, diffusion experiment on the soft solid material was made, the experimental results almost matched the predicted results given by the theoretical model.In Chapter6, all the work in this thesis was summed up, proposed innovations of the study, and the existing problems and the future researches on the needle-free injection system and a microneedle drug delivery system were involved.