Wu Sung-Yueh, Hsu Wensyang
Department of Mechanical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan.
Lab Chip. 2014 Aug 21;14(16):3101-9. doi: 10.1039/c4lc00421c.
This paper presents novel wireless EWOD/DEP chips that are wirelessly powered and controlled through LC circuits with one-to-many transmitter-receiver coupling. Each receiving LC circuit connected to the EWOD/DEP electrode is designed to have a different resonant frequency. When the input frequency is close to one of the resonant frequencies of receiving LC circuits, the induced voltage on the corresponding EWOD/DEP electrode will increase due to the resonance. Therefore, electrodes can be selectively and sequentially activated to provide sufficient EWOD or DEP force to manipulate the droplet or liquid by modulating the input frequency. Unlike previously reported wireless EWOD or DEP devices powered through one-to-one transmitter-receiver coupling, the transmitting inductor in the one-to-many transmitter-receiver coupling design proposed here is much larger than the total sizes of receiving inductors. Therefore, receiving inductors can be easily covered and coupled by the transmitting inductor. Here, droplet transport, splitting, and merging are successfully demonstrated using 5 receiving LC circuits at different input frequencies (1210-1920 Hz). Liquid pumping with multiple electrodes by wireless DEP is also demonstrated using 5 receiving LC circuits at higher input frequencies (51.2-76.1 kHz). Furthermore, liquid pumping with a continuous meandered electrode by wireless DEP is demonstrated through the resonant frequency shifting effect. It shows that the liquid pumping distance on a continuous electrode also can be tuned by proper frequency modulation.
本文介绍了一种新型无线电润湿/介电电泳（EWOD/DEP）芯片，该芯片通过具有一对多发射机-接收机耦合的LC电路进行无线供电和控制。连接到EWOD/DEP电极的每个接收LC电路都设计为具有不同的谐振频率。当输入频率接近接收LC电路的谐振频率之一时，由于谐振，相应EWOD/DEP电极上的感应电压会增加。因此，通过调制输入频率，可以选择性地、顺序地激活电极，以提供足够的电润湿或介电电泳力来操纵液滴或液体。与先前报道的通过一对一发射机-接收机耦合供电的无线EWOD或DEP设备不同，本文提出的一对多发射机-接收机耦合设计中的发射电感器比接收电感器的总尺寸大得多。因此，接收电感器可以很容易地被发射电感器覆盖并耦合。在这里，利用5个不同输入频率（1210 - 1920 Hz）的接收LC电路成功演示了液滴传输、分裂和合并。还利用5个更高输入频率（51.2 - 76.1 kHz）的接收LC电路演示了通过无线介电电泳实现的多电极液体泵送。此外，通过谐振频率偏移效应演示了利用连续曲折电极进行的无线介电电泳液体泵送。结果表明，连续电极上的液体泵送距离也可以通过适当的频率调制进行调节。
