面向细胞微操作的柔性并联压电定位台设计与实验

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KANGShengzheng，WANGHaowen

（School of Automation，Nanjing University of Information Science and Technology， Nanjing 210044，China） * Corresponding author， E-mail： kangsz@nuist. edu. cn

Abstract： In order to achieve cell-level operations such as cellcapture，cutting，separation，and injection， a flexible paralel piezoelectric positioning stage for biocellular engineering was designed，modeled，simulated，and tested in this paper.The positioning stage consisted of a moving platform，a base，a three-stage amplification mechanism，and three piezoelectric actuators.The displacements generated by the piezoelectric actuators were amplified by the three-stage amplification mechanism，and the precise movement of the positioning stage was realized through feedback control，so as to achieve the target positioning ffect. In the design process，the pseudo-rigid-body method combined with the flexible hinge stiffness calculation model was adopted to analyze the kinematic statics of the mechanism.The Lagrange equation was used to establish the dynamics model of the designed flexible parallel piezoelectric positioning stage using the lumped mass method.After determining the structural parameters，finite element analysis was carried out to verify the derived theoretical model，and the simulation results showed that the error between the theo retical and simulation models was less than 10% ，and the mechanism was able to achieve a large stroke as well as a higher frequency of motion. In addition，a prototype system for the flexible parallel piezoelectric positioning stage was also built and experimentally tested to evaluate its open and closed loop performance.The experimental results show that the designed positioning stage has a working stroke of 125μm×126μm ，the natural frequencies in the X -direction and Y -direction are 128.9Hz and 132.8Hz ， and the corresponding motion resolution are both better than 400nm ，respectively.

Key words ：cellmicromanipulation；piezoelectric actuators；flexible parallel mechanism；micro-positioning stage

1引言

随着生物医学的高速发展，现代生物医学研究的不断深入，许多细胞级的操作如细胞捕获、切割及注射等成为研究热点，在生物细胞工程的研究中，需要多自由度的精密操纵平台来实现微米级运动范围内的细胞甚至分子水平的复杂操作，因此研制一套高精度的柔性定位平台意义重大[-2]。（剩余16111字）