Samenvatting
Short liquid bridges are stable under the action of surface tension. In applications like electronic packaging, food engineering, and additive manufacturing, this poses challenges to the clean and fast dispensing of viscoelastic fluids. Here, we investigate how viscoelastic liquid bridges can be destabilized by torsion. By combining high-speed imaging and numerical simulation, we show that concave surfaces of liquid bridges can localize shear, in turn localizing normal stresses and making the surface more concave. Such positive feedback creates an indent, which propagates toward the center and leads to breakup of the liquid bridge. The indent formation mechanism closely resembles edge fracture, an often undesired viscoelastic flow instability characterized by the sudden indentation of the fluid’s free surface when the fluid is subjected to shear. By applying torsion, even short, capillary stable liquid bridges can be broken in the order of 1 s. This may lead to the development of dispensing protocols that reduce substrate contamination by the satellite droplets and long capillary tails formed by capillary retraction, which is the current mainstream industrial method for destabilizing viscoelastic liquid bridges.
| Originele taal-2 | Engels |
|---|---|
| Artikelnummer | e2104790118 |
| Aantal pagina's | 12 |
| Tijdschrift | Proceedings of the National Academy of Sciences of the United States of America (PNAS) |
| Volume | 118 |
| Nummer van het tijdschrift | 24 |
| DOI's | |
| Status | Gepubliceerd - 15 jun. 2021 |
Bibliografische nota
Funding Information:ACKNOWLEDGMENTS. S.T.C., A.M., S.J.H., and A.Q.S. acknowledge the support of Okinawa Institute of Science and Technology Graduate University with subsidy funding from the Cabinet Office, Government of Japan. S.T.C., A.M., S.J.H., and A.Q.S. also acknowledge financial support from the Japanese Society for the Promotion of Science (JSPS) (Grants 21J10517, 19K15641, 18K03958, 21K03884, and 18H01135) and the Joint Research Projects supported by the JSPS and the Swiss National Science Foundation. F.P.A.v.B. and P.D.A. thank Dr. M. A. Hulsen for providing access to the Toolkit for Finite Element Method software libraries. S.T.C. and H.A.F. thank Prof. H. C. Shum for fruitful discussions that helped conceive the research idea. We thank Prof. G. H. McKinley and Prof. R. I. Tanner for helpful comments.
Publisher Copyright:
© 2021 National Academy of Sciences. All rights reserved.
Financiering
ACKNOWLEDGMENTS. S.T.C., A.M., S.J.H., and A.Q.S. acknowledge the support of Okinawa Institute of Science and Technology Graduate University with subsidy funding from the Cabinet Office, Government of Japan. S.T.C., A.M., S.J.H., and A.Q.S. also acknowledge financial support from the Japanese Society for the Promotion of Science (JSPS) (Grants 21J10517, 19K15641, 18K03958, 21K03884, and 18H01135) and the Joint Research Projects supported by the JSPS and the Swiss National Science Foundation. F.P.A.v.B. and P.D.A. thank Dr. M. A. Hulsen for providing access to the Toolkit for Finite Element Method software libraries. S.T.C. and H.A.F. thank Prof. H. C. Shum for fruitful discussions that helped conceive the research idea. We thank Prof. G. H. McKinley and Prof. R. I. Tanner for helpful comments.