Dong Tao, Barbosa Cátia
Institute of Applied Micro-Nano Science and Technology, Chongqing Technology and Business University, Chongqing 400067, China.
Department of Micro and Nano Systems Technology (IMST), Faculty of Technology and Maritime Sciences (TekMar), Buskerud and Vestfold University College (HBV), Borre 3184, Norway.
Sensors (Basel). 2015 Jan 26;15(2):2694-708. doi: 10.3390/s150202694.
Microfluidic two-phase flow detection has attracted plenty of interest in various areas of biology, medicine and chemistry. This work presents a capacitive sensor using insulated interdigital electrodes (IDEs) to detect the presence of droplets in a microchannel. This droplet sensor is composed of a glass substrate, patterned gold electrodes and an insulation layer. A polydimethylsiloxane (PDMS) cover bonded to the multilayered structure forms a microchannel. Capacitance variation induced by the droplet passage was thoroughly investigated with both simulation and experimental work. Olive oil and deionized water were employed as the working fluids in the experiments to demonstrate the droplet sensor. The results show a good sensitivity of the droplet with the appropriate measurement connection. This capacitive droplet sensor is promising to be integrated into a lab-on-chip device for in situ monitoring/counting of droplets or bubbles.
微流控两相流检测在生物学、医学和化学等各个领域引起了广泛关注。这项工作提出了一种使用绝缘叉指电极（IDE）来检测微通道中液滴存在的电容式传感器。这种液滴传感器由玻璃基板、图案化金电极和绝缘层组成。与多层结构键合的聚二甲基硅氧烷（PDMS）盖形成微通道。通过模拟和实验工作深入研究了液滴通过引起的电容变化。实验中使用橄榄油和去离子水作为工作流体来演示液滴传感器。结果表明，在适当的测量连接下，液滴具有良好的灵敏度。这种电容式液滴传感器有望集成到芯片实验室设备中，用于原位监测/计数液滴或气泡。
