Acoustophoretic contactless elevation, orbital transport and spinning of matter in air.
We present the experimental demonstration and theoretical framework of an acoustophoretic concept enabling contactless, controlled orbital motion or spinning of droplets and particles in air. The orbital plane is parallel to gravity, requiring acoustophoretic lifting and elevation. The motion (spinning, smooth, or turnstile) is shown to have its origin in the spatiotemporal modulation of the acoustic field and the acoustic potential nodes. We describe the basic principle in terms of a superposition of harmonic acoustic potential sources and the intrinsic tendency of the particle to locate itself at the bottom of the total potential well.
Department of Mechanical and Process Engineering, Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, ETH Zurich, CH-8092 Zurich, Switzerland.
Daniele
D
Foresti
Department of Mechanical and Process Engineering, Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, ETH Zurich, CH-8092 Zurich, Switzerland.
Dimos
D
Poulikakos