We report a laser-micromachined electrolytic PCB micropump with an oil separation barrier. As advances in terms of miniaturization and performance from our previous mesoscale PCB electrolytic pump (Kim et al. in Sens Actuators A Phys 277:73–84, 2018), we employed a simple yet rapid tape-based laser-machining technique called tape-liner-supported plastic laser micromachining and pattern transfer to fabricate a microfluidic coverslip for a PCB electrode chip. Using our microfabrication technique, the coverslip is bonded to a PCB chip to form an enclosed microscale pump with a high machining precision and no need for alignment of intermediate adhesive tapes with structural layers as commonly done in previous tape-bonding work. The completed micropump demonstrated excellent pumping performance: flow rate up to 24.49 ml/min and backpressure up to 394 kPa. Electrochemical activation of electrodes consisting of a train of voltage pulses and sweeps improves the pumping performance. In order to prevent unwanted interspersion between the electrolyte and working fluid, various separation diaphragms were previously employed, but at the cost of limited working volume and flow rate as the diaphragms were permanently anchored to the pump body. Here we propose to use an oil plug as an untethered (mobile) separation barrier. After a systematic study of properties of common oils, we tested fluorinated oil (HFE-7500), hexadecane, and tetradecane as the candidate barrier materials. HFE-7500 was chosen because its interface was stable and did not degrade pumping performance for the flow-rate range of 8.47 μl/min–2.48 ml/min. We expect our micropump with the oil plug to be used as an excellent pressure source for integrated lab-on-a-chip devices, especially lab-on-a-PCBs.

我们报告了一种带有油分离屏障的激光微加工电解 PCB 微型泵。随着我们之前的中尺度 PCB 电解泵在小型化和性能方面的进步（Kim 等人，Sens Actuators A Phys 277:73–84, 2018），我们采用了一种简单而快速的基于胶带的激光加工技术，称为胶带-衬垫支持的塑料激光微加工和图案转移，为 PCB 电极芯片制造微流体盖玻片。使用我们的微细加工技术，将盖玻片粘合到 PCB 芯片上，形成一个封闭的微型泵，具有高加工精度，并且不需要像以前的胶带粘合工作中常见的那样将中间胶带与结构层对齐。完成的微型泵表现出出色的泵送性能：流量高达 24。49 毫升/分钟，背压高达 394 kPa。由一系列电压脉冲和扫描组成的电极的电化学激活提高了泵送性能。为了防止电解液和工作流体之间不必要的散布，以前使用了各种分离隔膜，但由于隔膜永久固定在泵体上，因此工作体积和流速受到限制。在这里，我们建议使用油塞作为不受限制的（移动）分离屏障。在对常见油品的特性进行系统研究后，我们测试了氟化油 (HFE-7500)、十六烷和十四烷作为候选阻隔材料。选择 HFE-7500 是因为它的界面稳定，并且在 8.47 μl/min–2.48 ml/min 的流速范围内不会降低泵送性能。