In Situ Visualization of Particle Motions during Wipe Sampling of Explosives and Other Trace Particulate Materials.

Surface texture tailoring has the potential to increase the effectiveness of dry particle collection wipes, as a wipe's topographical features control the intimate surface contact made with particles on the substrate (critical for van der Waals-governed adhesion). However, texture-tailoring approaches have not yet been widely explored, in part because of a lack of understanding of the specific wipe topographies and wipe/particle interactions that maximize particle collection. Here we describe an in situ optical microscopy technique that enables direct observation of micrometer-scale particle-wipe interactions occurring at the wipe-substrate interface during contact sampling.

Effect of re-use of surface sampling traps on surface structure and collection efficency for trace explosive residues.

In security settings, explosive residues or particles are collected by swiping the object of interest (e.g., luggage or package) with a collection medium, or trap.