Dielectrophoretic manipulation of rolled-up microtubes by surface acoustic waves

We present the dielectrophoretic manipulation of rolled-up metallic microtubes by surface acoustic waves (SAW) in a microfluidic capillary setup. The electric fields induced by a couple of counter-propagating SAWs forming a standing wave field allow to align conductive microtubes in solution along the acoustic propagation direction. In this work, we achieve controlled rotation of Cr microtubes in one-dimensional microfluidic channels by switching SAW propagation directions in 4-port devices. This technique combines the advantages of fast dielectrophoretic response and hydrodynamic control of tube movement.