Dynamics of Capillary-Driven Flow in 3D Printed Open Microchannels

Robert K. Lade, Erik J. Hippchen, Christopher W. Macosko, Lorraine F. Francis

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


Microchannels have applications in microfluidic devices, patterns for micromolding, and even flexible electronic devices. Three-dimensional (3D) printing presents a promising alternative manufacturing route for these microchannels due to the technology's relative speed and the design freedom it affords its users. However, the roughness of 3D printed surfaces can significantly influence flow dynamics inside of a microchannel. In this work, open microchannels are fabricated using four different 3D printing techniques: fused deposition modeling (FDM), stereolithography (SLA), selective laser sintering, and multi jet modeling. Microchannels printed with each technology are evaluated with respect to their surface roughness, morphology, and how conducive they are to spontaneous capillary filling. Based on this initial assessment, microchannels printed with FDM and SLA are chosen as models to study spontaneous, capillary-driven flow dynamics in 3D printed microchannels. Flow dynamics are investigated over short (∼10-3 s), intermediate (∼1 s), and long (∼102 s) time scales. Surface roughness causes a start-stop motion down the channel due to contact line pinning, while the cross-sectional shape imparted onto the channels during the printing process is shown to reduce the expected filling velocity. A significant delay in the onset of Lucas-Washburn dynamics (a long-time equilibrium state where meniscus position advances proportionally to the square root of time) is also observed. Flow dynamics are assessed as a function of printing technology, print orientation, channel dimensions, and liquid properties. This study provides the first in-depth investigation of the effect of 3D printing on microchannel flow dynamics as well as a set of rules on how to account for these effects in practice. The extension of these effects to closed microchannels and microchannels fabricated with other 3D printing technologies is also discussed.

Original languageEnglish (US)
Pages (from-to)2949-2964
Number of pages16
Issue number12
StatePublished - Mar 28 2017

Bibliographical note

Publisher Copyright:
© 2017 American Chemical Society.

MRSEC Support

  • Shared

PubMed: MeSH publication types

  • Journal Article
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't


Dive into the research topics of 'Dynamics of Capillary-Driven Flow in 3D Printed Open Microchannels'. Together they form a unique fingerprint.

Cite this