微流控芯片上油液磨粒电容检测

Microfluidic capacitance sensor for detecting metal wear debris in lubrication oil

报道一种可用来检测和计数油液中磨粒个数的微流控芯片实验室装置(microfluidic lab-on-chip).使用直径为25μm铜丝作为电极,在PDMS微流控芯片上加工获得三维电容传感器,油液样品在微流控芯片上由注射泵驱动通过传感器.金属磨粒与油液介电常数不同,每一个通过电容传感器的磨粒均会产生电容脉冲信号,脉冲信号幅值反映了磨粒大小,而脉冲个数即为磨粒数量,实现了最小粒径为8μm的铝磨粒的检测和计数.该油液磨粒检测装置具有结构简单、成本低、检测精度高等优点,有望应用于远洋船舶的油液离线分析.

This paper introduced a microfluidic lab-on-chip de- vice, which could be applied to detect the metal wear debris in the oil. Driven by the syringe pump, the sample oil in the inlet well of the PDMS microfluidic lab-on-chip passed through the ca- pacitance detection zone which has two 25 ixm-diameter copper wires acting as electrodes of a 3D capacitive sensor. Due to the different permittivity between the metal debris and the oil, each debris generated a capacitive pulse signal when passing through the capacitive sensor. The amplitude of this signal reflects the size of the grains, and the number of pulses is the quantity of the particles. With this device, the detection and counting debris of 81xm diameter are achieved. The device described is simple and in-expensive without losing high accuracy and sensitivity, which can be applied to develop a portable device for off-line oil analysis onboard ships.