@article{f5454a3433544b95b9fbd33389c5ed07,
title = "Acoustophoretic Liquefaction for 3D Printing Ultrahigh-Viscosity Nanoparticle Suspensions",
abstract = "An acoustic liquefaction approach to enhance the flow of yield stress fluids during Digital Light Processing (DLP)-based 3D printing is reported. This enhanced flow enables processing of ultrahigh-viscosity resins (μapp > 3700 Pa s at shear rates (Formula presented.) = 0.01 s–1) based on silica particles in a silicone photopolymer. Numerical simulations of the acousto–mechanical coupling in the DLP resin feed system at different agitation frequencies predict local resin flow velocities exceeding 100 mm s–1 at acoustic transduction frequencies of 110 s–1. Under these conditions, highly loaded particle suspensions (weight fractions, ϕ = 0.23) can be printed successfully in complex geometries. Such mechanically reinforced composites possess a tensile toughness 2000% greater than the neat photopolymer. Beyond an increase in processible viscosities, acoustophoretic liquefaction DLP (AL-DLP) creates a transient reduction in apparent viscosity that promotes resin recirculation and decreases viscous adhesion. As a result, acoustophoretic liquefaction Digital Light Processing (AL-DLP) improves the printed feature resolution by more than 25%, increases printable object sizes by over 50 times, and can build parts >3 × faster when compared to conventional methodologies.",
keywords = "3D printing, functional materials, polymer composites",
author = "Zheng Liu and Wenyang Pan and Kaiyang Wang and Yoav Matia and Artemis Xu and Barreiros, {Jose A.} and Cameron Darkes-Burkey and Giannelis, {Emmanuel P.} and Yiğit Meng{\"u}{\c c} and Shepherd, {Robert F.} and Wallin, {Thomas J.}",
note = "Funding Information: The authors thank Shuo Li, Hedan Bai, Maura O'Neill, Ronald Heisser, Chengyu Liu, and Yucheng Chen for helpful discussions. The authors thank Di Ni, Benyamin Davaji, and Adarsh Ravi for assistance on confocal sensor tests. The authors would like to acknowledge Viktor Lifton and Evonik for providing both research quantities of silica and technical support. The authors also thank Autodesk for generously gifting 3D printing hardware to contributing laboratories at Cornell. Portions of this study were performed at Cornell Center for Materials Research Shared Facilities and the Cornell Energy Systems Institute. These facilities are supported in part by NSF MRSEC program (Grant No. DMR‐1719875). Funding Information: The authors thank Shuo Li, Hedan Bai, Maura O'Neill, Ronald Heisser, Chengyu Liu, and Yucheng Chen for helpful discussions. The authors thank Di Ni, Benyamin Davaji, and Adarsh Ravi for assistance on confocal sensor tests. The authors would like to acknowledge Viktor Lifton and Evonik for providing both research quantities of silica and technical support. The authors also thank Autodesk for generously gifting 3D printing hardware to contributing laboratories at Cornell. Portions of this study were performed at Cornell Center for Materials Research Shared Facilities and the Cornell Energy Systems Institute. These facilities are supported in part by NSF MRSEC program (Grant No. DMR-1719875). Publisher Copyright: {\textcopyright} 2022 Facebook Technologies, LLC.",
year = "2022",
month = feb,
day = "1",
doi = "https://doi.org/10.1002/adma.202106183",
language = "English",
volume = "34",
journal = "Advanced Materials",
issn = "0935-9648",
publisher = "Wiley-Blackwell",
number = "7",
}