为解决SU-8胶微电热驱动器在工作过程中存在平面外运动的问题, 提出了一种具有铜-SU-8胶-铜三层对称结构的新型SU-8胶V形微电热驱动器。采用刚度矩阵方法建立了包含被驱动结构刚度的微电热驱动器力学模型, 并针对一种柔性微夹钳, 利用该模型对微电热驱动器进行了几何参数设计。利用Ansys仿真软件对所设计微驱动器进行了分析, 仿真结果验证了所建模型的合理性。提出了一种新的MEMS加工工艺来制作三层结构微电热驱动器, 并测试了它的性能。结果表明, 实验结果与仿真结果相差不大, 在150 mV驱动电压下, 所设计微驱动器温度仅升高约32.93°C, 并对微夹钳产生约2.5 μm的输入位移, 使微夹钳产生126 μm的钳口距离改变量。微驱动器仅消耗大约30.35 mW的功率, 钳口的平面外运动小于500 nm。最后, 利用微电热驱动器驱动的微夹钳成功地对一个长1.2 mm, 宽135 μm, 厚50 μm的SU-8胶材料微型零件进行了微操作实验, 实验证明了微驱动器实际性能基本满足设计要求。

To eliminate the out-of plane actuation of a SU-8 electrothermal micro-actuator, a novel SU-8 chevron electrothermal micro-actuator with a copper/SU-8/copper symmetrical structure was proposed. The mechanical model of the micro-actuator which contains the stiffness of a driven structure was established by using the stiffness matrix method. The geometric parameters of the micro-actuator were designed for a microgripper by using the established model. The designed micro-actuator was simulated by Ansys software and the simulation results verified the reasonability of the mechanical model. Then, the micro-actuator and the microgripper were fabricated by a simple process followed with a performance test. The test results show that when the temperature of the micro-actuator only increases 32.93℃ in a driving voltage of 150 mV, the output displacement is 2.5 μm and jaw gap change is 126 μm. During the operation processes, the out-of plane displacement of the tip is always lower than 500 nm. Finally, the micro-manipulation sequence of a SU-8 micro-part with a size of 1.4 mm×135 μm×50 μm was carried out to verify the driving ability of the micro-actuator.