Partial-post Laplace barriers for virtual confinement, stable displacement, and >5 cm s(-1) electrowetting transport.

Journal article

Laplace barriers composed of full-posts or ridges have been previously reported as a mechanism for virtual fluid confinement, but with unstable displacement (capillary fingering or fluid trapping, respectively). A new platform of 'partial-posts' eliminates the disadvantages of full-posts or ridges, while providing ~60-80% open channel area for rapid electrowetting fluid transport (>5 cm s(-1)). The fluid mechanics of partial-post Laplace barriers are far more complex than previous Laplace barriers as it involves two mechanisms: fluid can first begin to propagate either between, or under, the partial-posts. Careful design of channel and partial-post geometries is required, else one mechanism will dominate over the other. The physics and performance of partial-post Laplace barriers are verified using theoretical equations, experimental results, and dynamic numerical modeling.

Authors: Kreit, E; Mognetti, B; Yeomans, J; Heikenfeld, J

• Publication status: Published
• Journal: Lab on a chip
• Volume: 11
• Issue: 24
• Pages: 4221-4227
• Publication date: 2011-12-01
• DOI: 10.1039/c1lc20749k
• EISSN: 1473-0189
• ISSN: 1473-0197
• Language: English