Two-dimensional patterning of mesoscale fibers using acoustophoresis

The performance of functional composites can rely critically on the arrangement of secondary phases; for example, patterned networks of conductive particles can impart anisotropic thermal, electric or ionic conductivity while preserving flexibility in the matrix. We demonstrate the use of standing a...

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Main Authors: Keith E. Johnson, Brandon C. Montano, Kailino J. Nambu, Emilee N. Armstrong, Corie L. Cobb, Matthew R. Begley
Format: Article
Language:English
Published: Elsevier 2023-10-01
Series:Materials & Design
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S0264127523007438
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author Keith E. Johnson
Brandon C. Montano
Kailino J. Nambu
Emilee N. Armstrong
Corie L. Cobb
Matthew R. Begley
author_facet Keith E. Johnson
Brandon C. Montano
Kailino J. Nambu
Emilee N. Armstrong
Corie L. Cobb
Matthew R. Begley
author_sort Keith E. Johnson
collection DOAJ
description The performance of functional composites can rely critically on the arrangement of secondary phases; for example, patterned networks of conductive particles can impart anisotropic thermal, electric or ionic conductivity while preserving flexibility in the matrix. We demonstrate the use of standing acoustic waves to generate periodic patterns of short fibers. We extend the range of possible patterns with the first demonstration of both rectangular grids and arrays of octagons interspersed with rectangles. These newly demonstrated patterns are rationalized using theoretical models of acoustic forces and torques on fibers that account for two-dimensional spatial variations arising from applied acoustic fields. The models enable simulations of fiber motion, which are used to (i) map out final fiber positions as a function of initial position and orientation, and (ii) corroborate experiments visualizing fiber motion and final patterns. This approach provides a fast and accurate way to predict emergent fiber patterns as a function of excitation modality and fiber length. The theory and experiments clearly indicate strong coupling between the length of the fibers and the spacing of the acoustic nodes. This coupling is used to estimate reductions in percolation thresholds associated with the ratio of fiber length and acoustic wavelength.
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spelling doaj.art-3da687ba17f9472c9858c9a8a47f97f22023-10-28T05:06:29ZengElsevierMaterials & Design0264-12752023-10-01234112328Two-dimensional patterning of mesoscale fibers using acoustophoresisKeith E. Johnson0Brandon C. Montano1Kailino J. Nambu2Emilee N. Armstrong3Corie L. Cobb4Matthew R. Begley5Materials Department, University of California, Santa Barbara, United States of America; Corresponding authors.Department of Mechanical Engineering, University of California, Santa Barbara, United States of AmericaDepartment of Mechanical Engineering, University of California, Santa Barbara, United States of AmericaDepartment of Mechanical Engineering, University of Washington, United States of AmericaDepartment of Mechanical Engineering, University of Washington, United States of AmericaMaterials Department, University of California, Santa Barbara, United States of America; Department of Mechanical Engineering, University of California, Santa Barbara, United States of America; Corresponding authors.The performance of functional composites can rely critically on the arrangement of secondary phases; for example, patterned networks of conductive particles can impart anisotropic thermal, electric or ionic conductivity while preserving flexibility in the matrix. We demonstrate the use of standing acoustic waves to generate periodic patterns of short fibers. We extend the range of possible patterns with the first demonstration of both rectangular grids and arrays of octagons interspersed with rectangles. These newly demonstrated patterns are rationalized using theoretical models of acoustic forces and torques on fibers that account for two-dimensional spatial variations arising from applied acoustic fields. The models enable simulations of fiber motion, which are used to (i) map out final fiber positions as a function of initial position and orientation, and (ii) corroborate experiments visualizing fiber motion and final patterns. This approach provides a fast and accurate way to predict emergent fiber patterns as a function of excitation modality and fiber length. The theory and experiments clearly indicate strong coupling between the length of the fibers and the spacing of the acoustic nodes. This coupling is used to estimate reductions in percolation thresholds associated with the ratio of fiber length and acoustic wavelength.http://www.sciencedirect.com/science/article/pii/S0264127523007438Acoustic focusingAcoustophoresisFibersRodsPeriodic patterns
spellingShingle Keith E. Johnson
Brandon C. Montano
Kailino J. Nambu
Emilee N. Armstrong
Corie L. Cobb
Matthew R. Begley
Two-dimensional patterning of mesoscale fibers using acoustophoresis
Materials & Design
Acoustic focusing
Acoustophoresis
Fibers
Rods
Periodic patterns
title Two-dimensional patterning of mesoscale fibers using acoustophoresis
title_full Two-dimensional patterning of mesoscale fibers using acoustophoresis
title_fullStr Two-dimensional patterning of mesoscale fibers using acoustophoresis
title_full_unstemmed Two-dimensional patterning of mesoscale fibers using acoustophoresis
title_short Two-dimensional patterning of mesoscale fibers using acoustophoresis
title_sort two dimensional patterning of mesoscale fibers using acoustophoresis
topic Acoustic focusing
Acoustophoresis
Fibers
Rods
Periodic patterns
url http://www.sciencedirect.com/science/article/pii/S0264127523007438
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