Wang Yong, Qian Jingui
Department of Mechanical Engineering, Hangzhou City University, Hangzhou 310015, China.
The State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou 310027, China.
ACS Omega. 2023 Feb 14;8(8):7838-7844. doi: 10.1021/acsomega.2c07589. eCollection 2023 Feb 28.
Surface acoustic wave (SAW)-based acoustofluidic devices have shown broad applications in microfluidic actuation and particle/cell manipulation. Conventional SAW acoustofluidic device fabrication generally includes photolithography and lift-off processes and thus requires accessing cleanroom facilities and expensive lithography equipment. In this paper, we report a femtosecond laser direct writing mask method for acoustofluidic device preparation. By micromachining of steel foil to form the mask and direct evaporation of metal on the piezoelectric substrate using the mask, the interdigital transducer (IDT) electrodes of the SAW device are generated. The minimum spatial periodicity of the IDT finger is about 200 μm, and the preparation for LiNbO and ZnO thin films and flexible PVDF SAW devices is verified. Meanwhile, we have demonstrated various microfluidic functions, including streaming, concentration, pumping, jumping, jetting, nebulization, and particle alignment using the fabricated acoustofluidic (ZnO/Al plate, LiNbO) devices. Compared to the traditional manufacturing process, the proposed method omits spin coating, drying, lithography, developing, and lift-off processes and thus has advantages of simple, convenient, low cost, and environment friendliness.
基于表面声波（SAW）的声流控器件在微流体驱动以及颗粒/细胞操控方面展现出了广泛的应用。传统的SAW声流控器件制造通常包括光刻和剥离工艺，因此需要使用洁净室设施以及昂贵的光刻设备。在本文中，我们报道了一种用于制备声流控器件的飞秒激光直写掩膜方法。通过对钢箔进行微加工以形成掩膜，并使用该掩膜在压电基板上直接蒸发金属，从而生成SAW器件的叉指换能器（IDT）电极。IDT指的最小空间周期约为200μm，并且验证了LiNbO和ZnO薄膜以及柔性PVDF SAW器件的制备。同时，我们利用所制备的声流控（ZnO/Al板、LiNbO）器件展示了各种微流体功能，包括流动、浓缩、泵送、跳动、喷射、雾化以及颗粒排列。与传统制造工艺相比，所提出的方法省略了旋涂、干燥、光刻、显影和剥离工艺，因此具有简单、便捷、低成本和环境友好的优点。
