Structured channel metamaterials for deep sub-wavelength resolution in guided ultrasonics

John K. Birir; Michael J. Gatari; Prabhu Rajagopal

doi:10.1063/1.5143696

AIP Advances (Jun 2020)

Structured channel metamaterials for deep sub-wavelength resolution in guided ultrasonics

John K. Birir,
Michael J. Gatari,
Prabhu Rajagopal

Affiliations

John K. Birir: Institute of Nuclear Science and Technology, College of Architecture and Engineering, University of Nairobi, P.O Box 30197, 00100 Nairobi, Kenya
Michael J. Gatari: Institute of Nuclear Science and Technology, College of Architecture and Engineering, University of Nairobi, P.O Box 30197, 00100 Nairobi, Kenya
Prabhu Rajagopal: Center for Nondestructive Evaluation and Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, 600036 Tamil Nadu, India

DOI: https://doi.org/10.1063/1.5143696
Journal volume & issue: Vol. 10, no. 6
pp. 065027 – 065027-4

Abstract

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Experimental results on deep subwavelength resolution of defects are presented for the first time in the context of guided ultrasonic wave inspection of defects, using novel “structured channel” metamaterials. An Aluminum bar with side-drilled holes is used as a test sample, interrogated by the fundamental bar-guided symmetric mode. Simulations were conducted to optimize dimensional parameters of the metamaterial structure. Experiments using metamaterials fabricated accordingly demonstrate a resolution down to 1/72 of the operating wavelength, potentially bringing the resolution of guided wave inspection to the same range as that of bulk ultrasonics. This work has much promise for remote inspection in industry and biomedicine.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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