Trapping Generic Particles

Our paper, "Stable thermophoretic trapping of generic particles at low pressures" is published in Applied Physics Letters!

Check it out at Appl. Phys. Lett. 110, 034102 (2017)

For more informaton, take a look at the article in UChicago News or our Undergraduate student research.

We demonstrate levitation and three-dimensionally stable trapping of a wide variety of particles in a vacuum through thermophoretic force in the presence of a strong temperature gradient. Typical sizes of the trapped particles are between 10 μm and 1 mm at a pressure between 1 and 10 Torr. The trapping stability is provided radially by the increasing temperature field and vertically by the transition from the free molecule to hydrodynamic behavior of thermophoresis as the particles ascend. To determine the levitation force and test various theoretical models, we examine the levitation heights of spherical polyethylene spheres under various conditions. A good agreement with two theoretical models is concluded. Our system offers a platform to discover various thermophoretic phenomena and to simulate dynamics of interacting many-body systems in a microgravity environment.