Abstract
Liquid marbles need to be controlled precisely to benefit applications, for instance, as microreactors on digital microfluidic platforms for chemical and biological assays. In this work, a strategy is introduced to coalesce liquid marbles via electrostatics, where two liquid marbles in contact can coalesce when a sufficiently high voltage is applied to embedded electrodes. With the understanding of the mechanism of coalescence through relating the electric stress and the restoring capillary pressure at the contact interface, this method coalesces liquid marbles efficiently. When compared with the existing electrocoalescence method, our approach does not require immersion of electrodes to trigger coalescence. We demonstrate this to exchange the medium for the culture of cell spheroids and to measure the cell metabolic activity through a CCK-8 assay. The manipulation of liquid marbles driven by electrostatics creates new opportunities to conduct chemical reactions and biomedical assays in these novel microreactors. © The Royal Society of Chemistry.
| Original language | English |
|---|---|
| Pages (from-to) | 3526-3534 |
| Journal | Lab on a Chip |
| Volume | 19 |
| Issue number | 20 |
| Online published | 4 Sept 2019 |
| DOIs | |
| Publication status | Published - 21 Oct 2019 |
| Externally published | Yes |
Funding
We thank Prof. Huisheng Zhang, Dr. Zhou Liu, Dr. Tiantian Kong and Dr. Yuan Liu for their helpful discussions. We thank Mr. Hao Lyv for providing human mesenchymal stem cells. This research was supported by the General Research Fund (No. 17304514, 17306315, 17304017 and 17329516) from the Research Grants Council of Hong Kong, the Seed Fund for Basic Research (No. 201711159249, 201611159205 and 201511159280), the Seed Fund for Translational and Applied Research (No. 201711160016) from the University of Hong Kong and the Sichuan Science and Technology Program (2018JZ0026).