581 citations · 4.8k across the 83 of their papers we have counts for
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Acoustic radiation force on a heated spherical particle in a fluid including scattering and microstreaming from a standing ultrasound wave
Henrik Bruus, Bjørn G. Winckelmann
Analytical expressions are derived for the time-averaged, quasi-steady, acoustic radiation force on a heated, spherical, elastic, solid microparticle suspended in a fluid and locat…
The acoustic radiation force on a spherical thermoviscous particle in a thermoviscous fluid including scattering and microstreaming
Bjørn G. Winckelmann, Henrik Bruus
We derive general analytical expressions for the time-averaged acoustic radiation force on a small spherical particle suspended in a fluid and located in an axisymmetric incident a…
Constant-power versus constant-voltage actuation in frequency sweeps for acoustofluidic applications
Fabian Lickert, Henrik Bruus, Massimiliano Rossi
Supplying a piezoelectric transducer with constant voltage or constant power during a frequency sweep can lead to different results in the determination of the acoustofluidic reson…
Determination of the complex-valued elastic moduli of polymers by electrical impedance spectroscopy for ultrasound applications
William N. Bodé, Fabian Lickert, Per Augustsson +1
A method is presented for the determination of complex-valued compression and shear elastic moduli of polymers for ultrasound applications. The resulting values, which are scarcely…
Numerical study of acoustic cell trapping above elastic membrane disks driven in higher-harmonic modes by thin-film transducers with patterned electrodes
André G. Steckel, Henrik Bruus
Excitations of MHz acoustic modes are studied numerically in 10-um-thick silicon disk membranes with a radius of 100 and 500 um actuated by an attached 1-um-thick (AlSc)N thin-film…
A transition from boundary- to bulk-driven acoustic streaming due to nonlinear thermoviscous effects at high acoustic energy densities
Jonas Helboe Joergensen, Wei Qiu, Henrik Bruus
Acoustic streaming is studied in a rectangular microfluidic channel. It is demonstrated theoretically, numerically, and experimentally with good agreement, frictional heating can a…
Theory and modeling of nonperturbative effects at high acoustic energy densities in thermoviscous acoustofluidics
Jonas Helboe Joergensen, Henrik Bruus
A theoretical model of thermal boundary layers and acoustic heating in microscale acoustofluidic devices is presented. It includes effective boundary conditions allowing for simula…
Acoustophoresis in polymer-based microfluidic devices: modeling and experimental validation
Fabian Lickert, Mathias Ohlin, Henrik Bruus +1
A finite-element model is presented for numerical simulation in three dimensions of acoustophoresis of suspended microparticles in a microchannel embedded in a polymer chip and dri…
Fast microscale acoustic streaming driven by a temperature-gradient-induced non-dissipative acoustic body force
Wei Qiu, Jonas Helboe Joergensen, Enrico Corato +2
We study acoustic streaming in liquids driven by a non-dissipative acoustic body force created by light-induced temperature gradients. This thermoacoustic streaming produces a velo…
Bulk acoustofluidic devices driven by thin-film transducers and whole-system resonance modes
André G. Steckel, Henrik Bruus
In acoustofluidics, acoustic resonance modes for fluid and microparticle handling are traditionally excited by bulk piezoelectric transducers. In this work, we demonstrate by numer…
Numerical study of the coupling layer between transducer and chip in acoustofluidic devices
William Naundrup Bodé, Henrik Bruus
We study by numerical simulation in two and three dimensions the coupling layer between the transducer and the microfluidic chip in ultrasound acoustofluidic devices. The model inc…
Theory and simulation of AC electroosmotic suppression of acoustic streaming
Bjørn G. Winckelmann, Henrik Bruus
Acoustic handling of nanoparticles in resonating acoustofluidic devices is often impeded by the presence of acoustic streaming. For micrometer-sized acoustic chambers, this acousti…
Theory of pressure acoustics with thermoviscous boundary layers and streaming in elastic cavities
Jonas H. Joergensen, Henrik Bruus
We present an effective thermoviscous theory of acoustofluidics including pressure acoustics, thermoviscous boundary layers, and streaming for fluids embedded in elastic cavities.…
Particle-size-dependent acoustophoretic motion and depletion of micro- and nanoparticles at long time scales
Wei Qiu, Henrik Bruus, Per Augustsson
We present three-dimensional measurements of size-dependent acoustophoretic motion of microparticles with diameters from 4.8 um down to 0.5 um suspended in either homogeneous or in…
Suppression of acoustic streaming in shape-optimized channels
Jacob S. Bach, Henrik Bruus
Acoustic streaming is an ubiquitous phenomenon resulting from time-averaged nonlinear dynamics in oscillating fluids. In this theoretical study, we show that acoustic streaming can…
Theory of acoustic trapping of microparticles in capillary tubes
Jacob S. Bach, Henrik Bruus
We present a semi-analytical theory for the acoustic fields and particle-trapping forces in a viscous fluid inside a capillary tube with arbitrary cross section and ultrasound actu…
Bulk-driven acoustic streaming at resonance in closed microcavities
Jacob S. Bach, Henrik Bruus
Bulk-driven acoustic (Eckart) streaming is the steady flow resulting from the time-averaged acoustic energy flux density in the bulk of a viscous fluid. In simple cases, like the o…
Characterization of Acoustic Streaming in Gradients of Density and Compressibility
Wei Qiu, Jonas T. Karlsen, Henrik Bruus +1
Suppression of boundary-driven Rayleigh streaming has recently been demonstrated for fluids of spatial inhomogeneity in density and compressibility owing to the competition between…
Whole-system ultrasound resonances as the basis for acoustophoresis in all-polymer microfluidic devices
Rayisa P. Moiseyenko, Henrik Bruus
Using a previously well-tested numerical model, we demonstrate theoretically that good acoustophoresis can be obtained in a microchannel embedded in an acoustically soft, all-polym…
Theory of pressure acoustics with boundary layers and streaming in curved elastic cavities
Jacob S. Bach, Henrik Bruus
The acoustic fields and streaming in a confined fluid depend strongly on the acoustic boundary layer forming near the wall. The width of this layer is typically much smaller than t…
Theoretical aspects of microscale acoustofluidics
Henrik Bruus
Henrik Bruus is professor of lab-chip systems and theoretical physics at the Technical University of Denmark. In this contribution, he summarizes some of the recent results within…
Acoustic streaming and its suppression in inhomogeneous fluids
Jonas T. Karlsen, Wei Qiu, Per Augustsson +1
We present a theoretical and experimental study of boundary-driven acoustic streaming in an inhomogeneous fluid with variations in density and compressibility. In a homogeneous flu…
Three-Dimensional Numerical Modeling of Acoustic Trapping in Glass Capillaries
Mikkel W. H. Ley, Henrik Bruus
Acoustic traps are used to capture and handle suspended microparticles and cells in microfluidic applications. A particular simple and much-used acoustic trap consists of a commerc…
Acoustic Tweezing and Patterning of Concentration Fields in Microfluidics
Jonas T. Karlsen, Henrik Bruus
We demonstrate theoretically that acoustic forces acting on inhomogeneous fluids can be used to pattern and manipulate solute concentration fields into spatio-temporally controllab…