Design of thermophoretic probe for precise particle sampling

We proposed a design methodology for improved thermophoretic probes that can sample particles with high spatial resolution. A bending vibration analysis for the instantaneous motion of a probe has been done together with direct observation of the probe motion and flow disturbance for systematic study of the effect of different designs on particle sampling. Direct observation of the motion of thermophoretic sampling probes revealed that the probe with a low stiffness would result in inaccurate particle sampling. Based on these, the thermophoretic sampling probe was modified to minimize probe vibration and flow disturbance and this modified design was confirmed to sample particles with higher spatial resolution than the original one by examining transmission electron microscope (TEM) images of particles collected in a flame. (C) 2008 Elsevier Ltd. All rights reserved.