菲涅尔透镜聚焦声泳打印装置设计及实验研究*

针对现有的喷墨打印技术需根据喷印材料的特性定制而较难直接用于不同材料打印的问题，设计了一种基于菲涅尔透镜聚焦的声泳打印装置，该装置由超声发生器、超声换能器、菲涅尔透镜以及供液系统组成。首先，利用COMSOL软件模拟液滴在声辐射力作用下的滴落过程，并分析了超声发生器功率、喷嘴到基底距离、菲涅尔透镜厚度等参数对声场压力分布的影响，以及声场压力、喷嘴直径及材料粘度对液滴喷射过程的影响。其次，采用构建的声泳打印装置进行喷射成滴实验，通过调整超声发生器输出功率实现了不同粘度的聚乙二醇溶液的喷射以及UV胶的喷射。实验结果表明：该微滴喷射系统能产生一致性较好的微滴，喷印出的微透镜尺寸波动范围在2%以内，证明了该装置的稳定性以及实现了不同材料微滴喷射的可行性。

Design and experimental study of acoustophoretic printing using fresnel lenses

An acoustophoretic printing device based on Fresnel lens has been designed to address the existing problem that inkjet printing technology needs to be customized according to the properties of the material. COMSOL software is used to simulate the dropping process of liquid droplets under the action of acoustic radiation force, and the main parameters of the device are analyzed. Based on the parameters obtained from the simulation, an experimental device was established, which was composed of an ultrasonic generator, an ultrasonic transducer, a Fresnel lens and a liquid supply system. The experiment was carried out by using this device. By adjusting the output power of the ultrasonic generator, the injection of polyethylene glycol solution with mass fraction of 60 wt% and the formation of microlens array by spraying UV glue were realized. It is verified by experiments that the droplet injection system can produce droplets with good consistency, and the size fluctuation range of the microlens printed is within 2 %. The experimental results prove the stability of the device and the feasibility of realizing micro-droplet injection of different materials.