Tian Lu, Ye Zi, Gui Lin
Beijing Smart-Chip Microelectronics Technology Company, Ltd., Beijing 100192, China.
Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
Micromachines (Basel). 2021 Mar 23;12(3):340. doi: 10.3390/mi12030340.
This study presents a dielectrophoresis-based liquid metal (LM) droplet control microfluidic device. Six square liquid metal electrodes are fabricated beneath an LM droplet manipulation pool. By applying different voltages on the different electrodes, a non-uniform electric field is formed around the LM droplet, and charges are induced on the surface of the droplet accordingly, so that the droplet could be driven inside the electric field. With a voltage of ±1000 V applied on the electrodes, the LM droplets are driven with a velocity of 0.5 mm/s for the 2.0 mm diameter ones and 1.0 mm/s for the 1.0 mm diameter ones. The whole chip is made of PDMS, and microchannels are fabricated by laser ablation. In this device, the electrodes are not in direct contact with the working droplets; a thin PDMS film stays between the electrodes and the driven droplets, preventing Joule heat or bubble formation during the experiments. To enhance the flexibility of the chip design, a gallium-based alloy with melting point of 10.6 °C is used as electrode material in this device. This dielectrophoresis (DEP) device was able to successfully drive liquid metal droplets and is expected to be a flexible approach for liquid metal droplet control.
本研究展示了一种基于介电泳的液态金属（LM）微流控液滴控制装置。在一个LM液滴操控池下方制作了六个方形液态金属电极。通过在不同电极上施加不同电压，在LM液滴周围形成不均匀电场，并相应地在液滴表面感应出电荷，从而使液滴能够在电场中被驱动。当在电极上施加±1000 V电压时，对于直径为2.0 mm的LM液滴，驱动速度为0.5 mm/s；对于直径为1.0 mm的LM液滴，驱动速度为1.0 mm/s。整个芯片由聚二甲基硅氧烷（PDMS）制成，微通道通过激光烧蚀制作。在该装置中，电极不与工作液滴直接接触；在电极和被驱动液滴之间有一层薄的PDMS膜，可防止实验过程中产生焦耳热或形成气泡。为提高芯片设计的灵活性，该装置使用熔点为10.6 °C的镓基合金作为电极材料。这种介电泳（DEP）装置能够成功驱动液态金属液滴，有望成为一种灵活的液态金属液滴控制方法。
