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2019


The acoustic hologram and particle manipulation with structured acoustic fields
The acoustic hologram and particle manipulation with structured acoustic fields

Melde, K.

Karlsruher Institut für Technologie (KIT), May 2019 (phdthesis)

Abstract
This thesis presents holograms as a novel approach to create arbitrary ultrasound fields. It is shown how any wavefront can simply be encoded in the thickness profile of a phase plate. Contemporary 3D-printers enable fabrication of structured surfaces with feature sizes corresponding to wavelengths of ultrasound up to 7.5 MHz in water—covering the majority of medical and industrial applications. The whole workflow for designing and creating acoustic holograms has been developed and is presented in this thesis. To reconstruct the encoded fields a single transducer element is sufficient. Arbitrary fields are demonstrated in transmission and reflection configurations in water and air and validated by extensive hydrophone scans. To complement these time-consuming measurements a new approach, based on thermography, is presented, which enables volumetric sound field scans in just a few seconds. Several original experiments demonstrate the advantages of using acoustic holograms for particle manipulation. Most notably, directed parallel assembly of microparticles in the shape of a projected acoustic image has been shown and extended to a fabrication method by fusing the particles in a polymerization reaction. Further, seemingly dynamic propulsion from a static hologram is demonstrated by controlling the phase gradient along a projected track. The necessary complexity to create ultrasound fields with set amplitude and phase distributions is easily managed using acoustic holograms. The acoustic hologram is a simple and cost-effective tool for shaping ultrasound fields with high-fidelity. It is expected to have an impact in many applications where ultrasound is employed.

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link (url) DOI [BibTex]

2019



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Ferromagnetic colloids in liquid crystal solvents

Zarubin, G.

Universität Stuttgart, Stuttgart, 2019 (phdthesis)

icm

link (url) DOI [BibTex]

link (url) DOI [BibTex]


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Fluctuating interface with a pinning potential

Pranjić, Daniel

Universität Stuttgart, Stuttgart, 2019 (mastersthesis)

icm

[BibTex]

[BibTex]


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Controlling pattern formation in the confined Schnakenberg model

Beyer, David Bernhard

Universität Stuttgart, Stuttgart, 2019 (mastersthesis)

icm

[BibTex]

[BibTex]


Dynamics of self-propelled colloids and their application as active matter
Dynamics of self-propelled colloids and their application as active matter

Choudhury, U.

University of Groningen, Zernike Institute for Advanced Materials, 2019 (phdthesis)

Abstract
In this thesis, the behavior of active particles spanning from single particle dynamics to collective behavior of many particles is explored. Active colloids are out-of equilibrium systems that have been studied extensively over the past 15 years. This thesis addresses several phenomena that arise in the field of active colloids.

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link (url) [BibTex]

link (url) [BibTex]


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Interfaces in fluids of ionic liquid crystals

Bartsch, H.

Universität Stuttgart, Stuttgart, 2019 (phdthesis)

icm

link (url) DOI [BibTex]

link (url) DOI [BibTex]

2015


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Fluctuational electrodynamics for nonlinear media

Soo, H.

Universität Stuttgart, Stuttgart, 2015 (mastersthesis)

icm

[BibTex]

2015


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Evaporation and growth of liquid drops

Pöhnl, Ruben

Universität Stuttgart, Stuttgart, 2015 (mastersthesis)

icm

[BibTex]

[BibTex]

2011


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Simulation einer fast kritischen binären Flüssigkeit in einem Temperaturgradienten

Single, F.

Universität Stuttgart, Stuttgart, 2011 (mastersthesis)

icm

[BibTex]

2011


[BibTex]


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Struktur dichter ionischer Flüssigkeiten

Dannenmann, O.

Universität Stuttgart, Stuttgart, 2011 (mastersthesis)

icm

[BibTex]

[BibTex]


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Parallelisierung Stokesscher Dynamik für Graphikprozessoren zur Simulation kolloidaler Suspensionen

Kopp, M.

Universität Stuttgart, Stuttgart, 2011 (mastersthesis)

icm

[BibTex]

[BibTex]


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Diffusion in Wandnähe

Müller, J.

Universität Stuttgart, Stuttgart, 2011 (mastersthesis)

icm

[BibTex]

[BibTex]

2006


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Interfaces in fluids of charged platelike colloids

Bier, M.

Universität Stuttgart, Stuttgart, 2006 (phdthesis)

icm

link (url) [BibTex]

2006


link (url) [BibTex]


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Fluids in pores and gating in ion channels

Kroll, M.

Universität Stuttgart, Stuttgart, 2006 (mastersthesis)

icm

[BibTex]

[BibTex]


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Critical phenomena at chemically structured substrates

Sprenger, M.

Universität Stuttgart, Stuttgart, 2006 (phdthesis)

icm

link (url) [BibTex]

link (url) [BibTex]


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Density distributions in suspensions flowing around colloidal particles

Krüger, M.

Universität Stuttgart, Stuttgart, 2006 (mastersthesis)

icm

[BibTex]

[BibTex]