为实现对亚毫米微小构件稳定夹取及可靠释放等操作,研制了一种复合式微夹持器。采用有限元软件分析了微夹持器的机构及动力特性。应用MEMS体硅工艺将静电梳齿驱动与气动吸放集成构成复合式驱动,气动吸放的引入改善了微夹持器的操作性能,S形柔性梁结构的设计将梳齿驱动的直线运动转化成末端夹爪的转动实现了夹持操作。两种不同尺寸的微夹持器,有效扩展了微夹持器的夹持范围。根据微夹持器的操作控制需求,设计了微夹持器静电驱动控制系统以及气压控制系统。在80 V的驱动电压下,微夹持器末端夹爪位移可达25 μm。针对100～200 μm的小球进行了微操作实验,实验结果表明,静电梳齿驱动结合真空吸附能够使夹取操作更加稳定,基于闭环控制的气路正压力能有效克服小球与夹爪之间的粘附力,实现可靠的释放操作。微夹持器基本满足100～200 μm微小构件的操作需求。

In order to realize the steady and reliable operations of microobjects,a hybrid-type electrostatic silicon microgripper integrated with gas pipes for aspirating and blowing operations is developed and its structure and dynamic characteristics are analyzed by the Finite Elemenl Analysis(FEA).Gas pipes integrated in this novel microgripper are used to improve its picking and placing capability and a bulk micromachining technology is employed to fabricate the microgripper from single crystal silicon wafers.The linear horizontal motion generated by an electrostatic microactuator is converted into the rotational motion of the arm by the S-type flexible beam system to realize the gripping motion.Moreover,the grippers with two different dimensions are designed to expand the manipulating range and the gas pressure control system and electrostatic comb drive control system are designed for controlling the microgripper.Experiments show that the deflection is 25 μm at the arm tip of the gripper in a driving voltage of 80 V,and the microobjects can be picked and placed successfully from 100 μm to 200 μm in the experiment,which indicates that this microgripper realizes the steady manipulation and can satisfy the micromanipulation of the microobjects from 100 μm to 200 μm.