High-Efficiency Enrichment of Metallic Particles in\nLubricating Oil Based on Filter-Free Acoustic Manipulation Chip

Enrichment\nof metal particles in lubricating oil is a crucial pretreatment\nfor wear debris analyses in applications of condition-based machinery\nmaintenance. Current techniques using physical filter cleaning and\nmagnetic attachment to enrich metal particles have limitations in\nterms of efficiency and selectivity. This work presents an innovative\nacoustic manipulation chip for efficiently enriching metallic particles\nfrom lubricating oil. The platform utilizes the hybrid acoustic forces\nto perform high throughput particle enrichment in microchannels, even\nin an intensive flow environment. Regarding the viscosity effect of\nlubricating oil, the temperature dependence upon the particle enrichment\nis explored, and the figure of merit is employed to quantify the enrichment\nperformance from the captured microscopic images. Experimental results\ndemonstrate the proposed platform shows great nonselectivity for enriching\nboth magnetic and nonmagnetic particles. This method opens a new door\nfor developing automatic filter-free pretreatment tools to perform\nefficient particle enrichment in lubricating oil, which have great\npotential in many application scenarios, such as advanced wear debris\nanalyses, oil quality monitoring, etc.