The traditional power sources for generating droplets are bulky devices such as syringe pumps, constant pressure systems and so on, resulting in difficult integration with other microfluidic components. To overcome this limitation, we propose and develop a droplet generator with its power sources on a chip (22 × 21 × ~ 1 mm). The compact droplet generator consists of two ECF (electro-conjugate fluid) micropumps, a T-junction channel geometry made of SU-8, a water chamber and three I/O ports. In our methodology, the two ECF micropumps are used to pump the continuous phase fluid (oil) directly and the dispersed phase fluid (water) indirectly on a chip. ECF is a kind of functional and dielectric oil, which can generate a strong and active ECF jet when its corresponding electrodes are applied to high DC voltages. Our ECF micropump is composed of triangular prism and silt electrode pairs (TPSEs) and is able to control flow rates precisely on a chip. In our device, the water in oil droplet is formed by the T-junction geometry. Using MEMS technology, we successfully fabricate the droplet-generator-on-a-chip. Span 80 and dibutyl decanedioate (DBD, Tokyo Chemical Industry Co., Ltd) are used as the surfactant and one type of ECF, respectively. Prior to the characteristic experiments of the T-junction generator, we investigate viscosity, electrical conductivity and relative permittivity of the mixtures of DBD and Span 80 at different concentrations (0 wt%, 1 wt%, 3 wt% and 5 wt%). We also research the impact of the mixtures on the performance of ECF micropumps and the wettability of SU-8 fluidic channels. After that, we confirm the flow pattern diagrams of two-phase fluids, the generated droplet diameter and the droplet production rate for our droplet-generator. Therefore, our droplet generator powered by ECF micropumps can realize the droplet generation on a chip.

用于产生液滴的传统电源是笨重的设备，例如注射泵，恒压系统等，导致难以与其他微流体组件集成。为了克服这一限制，我们提出并开发了一种液滴发生器，其电源在一个芯片上（22×21×〜1 mm）。紧凑型液滴发生器由两个ECF（电共轭流体）微泵，一个由SU-8制成的T型结通道几何形状，一个水室和三个I / O端口组成。在我们的方法中，使用两个ECF微型泵将连续相流体（油）直接泵入，将分散相流体（水）间接泵入芯片。ECF是一种功能性和介电油，当将其相应的电极施加到高DC电压时，它可以产生强而活跃的ECF射流。我们的ECF微型泵由三角棱镜和淤泥电极对（TPSE）组成，能够精确地控制芯片上的流速。在我们的设备中，油滴中的水是由T型结形成的。使用MEMS技术，我们成功地制造了单片微滴发生器。Span 80和癸二酸二丁酯（DBD，东京化学工业有限公司）分别用作表面活性剂和一种ECF。在T型结发生器的特性实验之前，我们研究了DBD和Span 80混合物在不同浓度（0 wt％，1 wt％，3 wt％和5 wt％）下的粘度，电导率和相对介电常数。我们还研究了混合物对ECF微型泵性能和SU-8流体通道的润湿性的影响。在那之后，我们确定了两相流体的流型图，产生的液滴直径和液滴发生器的液滴生产率。因此，我们由ECF微型泵驱动的液滴发生器可以在芯片上实现液滴的产生。