Theoretical And Experimental Research On The New Parallel Micro-motion Platform Based On Biological Egnginering

With the rapid development of bio-engineering, people are gradually paying theirattention to operating and positioning platform with micro-nano level. In order to meet thedemand of micro operation field such as bio-engineering, it is a great significance that anew parallel micro-motion platform with approximate decoupling characteristic ofthree–dimensional movement is proposed.In this paper, in connection with the micro-operation of the cell injection inbio-engineering, a new parallel micro-motion platform driven by PZT is proposed anddesigned based on3-PRC parallel mechanism. Its main contents are as follows:Based on3-PRC parallel mechanism, a initial configuration of3-PRC parallelmicro-motion platform with flexible hinge is proposed and designed by adopting flexiblekinematic pair instead of the traditional kinematic pair and placing three branched chainsin the space orthogonally, and the final configuration is attained by optimizing the flexiblekinematic pair in configuration.The micro-motion platform is theoretically analyzed with its stiffness and bridge-typedisplacement amplifying structure by means of flexibility matrix transformation, and thenthe magnification ratio formula of stiffness matrix and bridge-type displacementamplifying structure for the micro-motion platform is obtained, and the formula isanalyzed and verified by using the software of FEA.A kinematical equation is established by using vector method, and the inverse andpositive position solutions for the parallel micro-motion platform will be obtained. Afterthe theoretical coupling error analysis as well as the analysis of finite element simulationin different loading conditions on the micro-motion platform, it is proved that the parallelmicro-motion platform has the motion characteristics of three-dimensional movement thatapproximates decoupling.Through using Lagrange equation and mass concentration method, the kineticequation of the micro-motion platform is built and its natural vibration frequency will becalculated accordingly. By using mode simulation with FEA software, the first sixvibration frequencies of micro-motion platform will be obtained, which plays a role in avoiding resonance of the whole micro-motion platform.A experimental prototype of3-PRC parallel micro-motion platform is made,experimented and studied. The experiments include the displacement amplification of asingle branched chain and motion decoupling for the whole micro-motion platform invarious conditions. Through the analysis on experimental results, it is proved that this3-PRC parallel micro-motion platform has good linear input-output relation ofthree-dimension decoupling, can achieve the range of motion and positioning accuracy inmicro-nano level, and can meet the operational demand of micro-injection inbio-engineering.