[Lab on a chip] Controlled rotation and translation of spherical particles or living cells by surfac
We show experimental evidence of the acoustically-assisted micromanipulation of small objects like solid particles or blood cells, combining rotation and translation, using high frequency surface acoustic waves. This was obtained from the leakage in a microfluidic channel of two standing waves arranged perpendicularly in a LiNbO3 piezoelectric substrate working at 36.3 MHz. By controlling the phase lag between the emitters, we could, in addition to translation, generate a swirling motion of the emitting surface which, in turn, led to the rapid rotation of spherical polystyrene Janus beads suspended in the channel and of human red and white blood cells up to several rounds per second. We show that these revolution velocities are compatible with a torque caused by the acoustic streaming that develops at the particles surface, like that first described by [F. Busse et al., J. Acoust. Soc. Am., 1981, 69(6), 1634–1638]. This device, based on standard interdigitated transducers (IDTs) adjusted to emit at equal frequencies, opens a way to a large range of applications since it allows the simultaneous control of the translation and rotation of hard objects, as well as the investigation of the response of cells to shear stress.
Ianis Bernard,a Alexander A. Doinikov,a Philippe Marmottant,a David Rabaud,b Cédric Poulainb and Pierre Thibault*a Author affiliations * Corresponding authors a CNRS/Université Grenoble-Alpes, LIPhy UMR 5588, Grenoble, France E-mail: Pierre.Thibault@univ-grenoble-alpes.fr Fax: +33 (0)476 635 495 Tel: +33 (0)668 104 915 b LETI MINATEC Campus, Univ. Grenoble Alpes, CEA, F-38000 Grenoble, France