Contact
    Start Publications Torsional fracture of viscoelastic liquid bridges
    ←  Publication Finder
    Attension

    Torsional fracture of viscoelastic liquid bridges

    Year: 2021

    Journal: Proc. Natl. Acad. Sci. U. S. A., Volume 118, JUN 15

    Authors: Chan, San To; van Berlo, Frank P. A.; Faizi, Hammad A.; Matsumoto, Atsushi; Haward, Simon J.; Anderson, Patrick D.; Shen, Amy Q.

    Organizations: Okinawa Institute of Science and Technology Graduate University; Cabinet Office, Government of Japan; Japanese Society for the Promotion of Science (JSPS) [21J10517, 19K15641, 18K03958, 21K03884, 18H01135]; JSPS; Swiss National Science Foundation

    Keywords: edge fracture; viscoelasticity; liquid bridge; flow instability; contact printing

    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.
    View publication