TY - JOUR
T1 - An unrecognized inertial force induced by flow curvature in microfluidics
AU - Agarwal, Siddhansh
AU - Chan, Fan Kiat
AU - Rallabandi, Bhargav
AU - Gazzola, Mattia
AU - Hilgenfeldt, Sascha
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank Kaitlyn Hood, Gabriel Juarez, and Howard A. Stone for fruitful discussions. This work was supported by NSF CAREER Grant CBET-1846752 (to M.G.) and by the Blue Waters project (Grants OCI-0725070 and ACI-1238993), a joint effort of the University of Illinois at Urbana–Champaign and its National Center for Supercomputing Applications. This work also used the Extreme Science and Engineering Discovery Environment Stampede2, supported by NSF Grant ACI-1548562, at the Texas Advanced Computing Center through Allocation TG-MCB190004.
Publisher Copyright:
© 2021 National Academy of Sciences. All rights reserved.
PY - 2021/7/20
Y1 - 2021/7/20
N2 - Modern inertial microfluidics routinely employs oscillatory flows around localized solid features or microbubbles for controlled, specific manipulation of particles, droplets, and cells. It is shown that theories of inertial effects that have been state of the art for decades miss major contributions and strongly underestimate forces on small suspended objects in a range of practically relevant conditions. An analytical approach is presented that derives a complete set of inertial forces and quantifies them in closed form as easy-to-use equations of motion, spanning the entire range from viscous to inviscid flows. The theory predicts additional attractive contributions toward oscillating boundaries, even for density-matched particles, a previously unexplained experimental observation. The accuracy of the theory is demonstrated against full-scale, three-dimensional direct numerical simulations throughout its range.
AB - Modern inertial microfluidics routinely employs oscillatory flows around localized solid features or microbubbles for controlled, specific manipulation of particles, droplets, and cells. It is shown that theories of inertial effects that have been state of the art for decades miss major contributions and strongly underestimate forces on small suspended objects in a range of practically relevant conditions. An analytical approach is presented that derives a complete set of inertial forces and quantifies them in closed form as easy-to-use equations of motion, spanning the entire range from viscous to inviscid flows. The theory predicts additional attractive contributions toward oscillating boundaries, even for density-matched particles, a previously unexplained experimental observation. The accuracy of the theory is demonstrated against full-scale, three-dimensional direct numerical simulations throughout its range.
KW - Inertial microfluidics | oscillatory flows | particle manipulation
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U2 - 10.1073/pnas.2103822118
DO - 10.1073/pnas.2103822118
M3 - Article
C2 - 34261792
AN - SCOPUS:85110311572
VL - 118
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 29
M1 - e2103822118
ER -