Research On Dynamic Characteristics And Manufacturing Process Of Micro Movable Tooth Transmission System

Electromagnetically driven movable tooth transmission system is a kind of micro-actuator integrating electromagnetic drive control technology and micro-electromechanical system(MEMS)manufacturing technology.It has the advantages of compact structure,load carrying capacity and large transmission ratio.Because the electromagnetic driving mechanism belongs to the energy conversion process harmless to biological tissues,it has good biocompatibility and has broad application prospects in micro-robot joint drive,cell-level drug release and micro-particle transport.In this thesis,an external wave micro-plane movable tooth transmission system is designed.The mechanics characteristics and manufacturing process of the movable tooth transmission system is studied.The main research contents are as follows:The driving principle and structural composition of the movable tooth transmission system are explained.The molecular force in the system is solved by Hamaker's hypothesis,and the static equation of the system is deduced when considering the molecular force.The Hertz contact theory is used to analyze the bearing capacity and molecular force in the system,and influence of the molecular force on structural mechanical properties.The results show that van der Waals force has a significant influence on the contact stress of the movable tooth transmission system.When considering van der Waals force,the eccentricity of the wave generator and the radius of the movable tooth have the greatest influence on the contact stress of the movable tooth.By simplifying the transmission part of the movable tooth transmission system,the free vibration model of the system is established.The Newton's second law is applied to derive the dynamic equation of the system.The natural frequency and mode shape of the system are obtained by solving the equation.The influence of the main parameters on the natural frequency is studied.The results show that the geometric parameters and stiffness of the movable tooth transmission system have a significant influence on the natural frequency of the system.According to the structural characteristics of the parts of the movable tooth transmission system,the corresponding electron beam lithography process flow is designed.The influence of main parameters(exposure dose and development time)on the lithography experiment in the electron beam lithography process is analyzed and optimized.The results show that by controlling the exposure dose and development time,the better quality photoresist mold of wave generator,central ring and guide frame can be processed.Using the high vacuum evaporation coating technology,the influence of the rate of evaporation coating on the processing quality of the parts is analyzed.The processing of the wave generator and the central ring in the micro movable tooth structure is realized based on the silicon substrate and the glass substrate.Handling of system parts is completed on the glass substrate.The results show that the optimal quality of the wave generator and the central ring can be processed through the optimized coating process parameters.The bonding strength between the glass substrate and the metal parts is weak,and the peeling and manipulation of the parts can be easily realized based on the glass substrate.