基于声表面波(SAW)驱动机理设计并仿真了一种微混合器,制备了由4个谐振频率为49.1 MHz的铜叉指式换能器(IDT)构成的SAW驱动的微混合器(IDT采用剥离工艺制备,使用的基片材料为128°YX型铌酸锂,每个IDT有5个叉指对,周期为80μm,指条宽度为5 μm,指条厚度为1.6μm),搭建了基于SAW微混合器驱动的微混合平台,实现了3μL甘油与1μL墨水两种液滴间的混合以及3μL蒸馏水液滴和平均直径为1.5tμm的红色微粒之间的混合.实验结果证明,在驱动功率为9W、驱动频率为49.13 MHz的电信号激励下,SAW微混合器可实现液滴间以及液滴和微粒间在1 s内的高速混合,并且液滴内部运动与其位于SAW微混合器的位置有关.“,”A micro mixer was designed and simulated based on surface acoustic wave (SAW) driving mechanism.The SAW micro mixer is consisted of four copper interdigital transducers (IDT) with the resonance frequency of 49.1 MHz (With the 128°YX LiNbO3 as the substrate material,the IDT was fabricated by the lift-off process.Each IDT has five strip pairs,the period of the IDT is 80μm,the strip width is 5μm and the thickness is 1.6μm).A micro hybrid platform based on the SAW micro mixer was constructed.The mixing between a glycerol droplet and an ink droplet,between the red particles and a distilled water droplet were experimentally realized,respectively.The volumes of the glycerol droplet and the distilled water droplet are 3 μL respectively,the volume of the ink droplet is 1μL and the average diameter of the red particles is 1.5 μm.The experiment results prove that the high-speed mixing of two droplets and between one droplet and one particle can all be completed within 1 s under the excitation of the electric signal with the driving power of 9 W and the driving frequency of 49.13 MHz,and the internal motion of the droplet is related with its position in the SAW micro mixer.