A microfluidic Coulter counting device for metal wear detection in lubrication oil.

We present the design, fabrication, and testing of a microfluidic device for metal wear detection in lubrication oils. The detection is based on the capacitance Coulter counting principle, that is, on the change in a microchannel's capacitance caused by the presence of a metal particle in the microchannel. The testing of the microfluidic device using 10-25 microm aluminum particles has demonstrated the feasibility for detection and counting of microscale metal particles in low-conductive lubrication oils. This microfluidic device is promising for online oil debris detection by the use of multiple detection microfluidic channels.