Multi-directional bubble generated streaming flows

Spelman, T. A., Stephan, O. and Marmottant, P. (2020) Multi-directional bubble generated streaming flows. Ultrasonics, 102, 106054. (doi: 10.1016/j.ultras.2019.106054) (PMID:31948810)

Abstract

In previous work, we have demonstrated the use of single-holed Armoured Microbubbles (AMBs) for microfluidic mixing and self-propulsion. AMBs are hollow partial spheres, inside which we capture a bubble. Under ultrasound, the bubble oscillates, generating a streaming flow with velocities of 1–100 mm/s in water. In this paper, inspired by our successful fabrication of a C60 geometry (buckyball), we study AMBs with multiple surface holes. We show more holes generate additional pairs of fast circulations around the AMB. However, as the number of holes increases further, the circulations become small and the in-plane flow is dominated by a source or sink flow. For an AMB with two different sized holes, we demonstrate each hole can be independently activated, potentially useful for multi-directional swimming.

• Item Type: Articles
• Additional Information: P.M. acknowledge financial support from the European Community’s Seventh Framework Programme (FP7/2007-2013) ERC Grant Agreement Bubbleboost no. 614655. T.A.S. would like to thank Prof Eric Lauga for support to travel to the laboratories at the Universite Grenoble Alpes to perform these experiments, including for partial financial support from the European Union’s Horizon 2020 research and innovation programme (Grant No. 682754 to Eric Lauga). T.A.S. also acknowledges a travel grant form the Cambridge Philosophical Society.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Spelman, Dr Tamsin Anne
• Authors: Spelman, T. A., Stephan, O., and Marmottant, P.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Mathematics
• Journal Name: Ultrasonics
• Publisher: Elsevier
• ISSN: 0041-624X
• ISSN (Online): 1874-9968
• Published Online: 02 December 2019