System and method for oil condition monitoring

A microfluidic system for monitoring the condition of lubricating oil comprising:

• a microfluidic device comprising at least one microchannel configured to allow a sample of lubricating oil to pass therethrough as a laminar flow;
• and a
• at least one separating device configured to selectively separate at least one component from the lubricating oil in the fluid flow, wherein the at least one separating device comprises a diffusion extractor configured to allow diffusion across the fluid interface of parallel fluid streams;
• wherein the microfluidic system comprises a detector device configured to detect the presence and/or measure at least one property of the at least one component passing through the microfluidic device after separation in the at least one microchannel.