Improving the performance of electrowetting on dielectric microfluidics using piezoelectric top plate control
Improving the performance of electrowetting on dielectric microfluidics using piezoelectric top plate control
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DOI：
10.1016/j.snb.2016.01.108
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发表时间：
2016-06-28
影响因子：
8.4
通讯作者：
Raad, Dominic
中科院分区：
文献类型：
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作者：
Li, Yiyan;Baker, R. Jacob;Raad, Dominic
本研究提出了一种智能EWOD顶板控制系统。动态顶板由压电（PZT）悬臂结构控制。高分辨率激光位移传感器用于监测顶板的偏转。间隙高度优化和顶板振动显着提高了液滴速度并降低了液滴最小阈值驱动电压。顶板振动引起的致动速度改进取决于幅度和频率。 100 针和 200 针振动在 25 Hz 下进行测试。测试振动频率为5Hz、10Hz、20Hz，震级为200pin。结果表明，在更大的振动幅度和更高的振动频率下可以实现更大的改进。使用振动顶板时，对于 2.0 µl DI 水滴，致动电压的最大降低为 76 V-RMS。最大液滴瞬时速度约为9.3 mm/s，几乎比驱动电压不足时无顶板振动的液滴速度快3倍。使用具有不同滞后作用的液体（例如不同浓度的乙腈）作为对照，以显示其与所提出的 DMF 芯片的兼容性。观察到顶板振动下的接触线脱钉，这表明了驱动速度和阈值电压改进的潜在机制。本研究报告的顶板控制技术使 EWOD DMF 芯片在用于临床护理点诊断应用时更加可靠。 (C) 2016 Elsevier B.V. 保留所有权利。
An intelligent EWOD top plate control system is proposed in this study. The dynamic top plate is controlled by a piezoelectric (PZT) cantilever structure. A High resolution laser displacement sensor is used to monitor the deflection of the top plate. The gap height optimization and the top plate vibration significantly improve the droplet velocity and decrease the droplet minimum threshold actuation voltage. The top plate vibration induced actuation velocity improvement is magnitude and frequency dependent. 100 pin and 200 pin vibrations are tested at 25 Hz. Vibration frequencies at 5 Hz, 10 Hz, and 20 Hz are tested while the magnitude is 200 pin. Results show greater improvements are achieved at larger vibration magnitudes and higher vibration frequencies. With a vibrated top plate, the largest reduction of the oactuation voltage is 76 V-RMS for a 2.0 mu l DI water droplet. The maximum droplet instantaneous velocity is around 9.3 mm/s, which is almost 3 times faster than the droplet velocity without top plate vibration under insufficient driving voltages. Liquid that has different hysteresis such as acetonitrile with various concentrations are used as a control to show its compatibility with the proposed DMF chip. Contact line depinning under top plate vibration is observed, which indicates the underlying mechanism for the improvements in actuation velocity and threshold voltage. The top plate control technique reported in this study makes EWOD DMF chips more reliable when used for the clinical point-of-care diagnostic applications. (C) 2016 Elsevier B.V. All rights reserved.