A Novel Method Based on Optofluidic Lensless-Holography for Detecting the Composition of Oil Droplets

A novel method based on optofluidic lensless-holography for detecting the composition of oil droplets is presented in this paper. The three most important characteristic parameters in the holograms of oil droplets and particles with different sizes were compared and analyzed, and the correlation between the characteristic parameters and the molecular structure (different number of carbon-hydrogen bonds) of oil droplet was determined. In addition, the experimental results show that the detection results of the newly developed lensless holographic imaging system are not affected by the surface properties of oil droplets. By detecting PEA (amino-terminated polyoxypropylene, a fuel additive), it is demonstrated that the developed method is sufficiently sensitive to the trace amount of additives or impurities in the oil. To the best of our knowledge, this is the first time that the lensless-holography combined with the optofluidic technology has been used to detect the composition of oil droplets. The portability of the developed device is very suitable for real-time on-site detection.