Abrasive jet micro-machining (AJM) uses a high-velocity particle jet to erode features in target substrates for a variety of applications, including micro-electro-mechanical and micro-fluidic device fabrication. AJM can result in a dusty environment due primarily to airborne, rebounding abrasive particles that eventually settle. This paper proposes a novel concept of covering the target with a layer of liquid in order to improve the process cleanliness. Films of water, glycerin, and a polymer solution were used to investigate the effect of liquid viscosity and film thickness on the percentage of captured particles, and also on the depth, width, erosion rate, roughness, and waviness of abrasive jet micro-machined channels. The glycerin film captured up to 61% of the rebounding particles during the machining of micro-channels. The channel depth, width, erosion rate, and roughness decreased, and the channel centreline waviness increased. Films of the long-chain polymer solution and of pure water absorbed up to 42% and 36%, respectively, of the rebounding particles, while not significantly changing the channel depth, width, roughness, and waviness. For all liquids, the percentage of trapped particles increased with increasing film thickness. The results showed that AJM with the target covered by a thin liquid film is a viable way of increasing process cleanliness by decreasing the amount of airborne particulates. (C) 2016 Elsevier B.V. All rights reserved.