Laser-Based Ultrasound Interrogation of Surface and Sub-Surface Features in Advanced Manufacturing Materials

Abstract Structures formed by advanced manufacturing methods increasingly require nondestructive characterization to enable efficient fabrication and to ensure performance targets are met. This is especially important for aerospace, military, and high precision applications. Surface acoustic waves (SAW) generated by laser-based ultrasound can detect surface and sub-surface defects relevant for a broad range of AM processes, including laser powder bed fusion (LPBF). In particular, an all-optical SAW generation and detection configuration can effectively interrogate laser melt lines. Here we report on scattered acoustic energy from melt lines, voids, and surface features. Sub-surface voids are also characterized using X-ray Computed Tomography (CT). High resolution CT results are presented and compared with SAW measurements. Finite difference simulations inform experimental measurements and analysis.

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Fast Inertial Microfluidic Actuation and Manipulation Using Surface Acoustic Waves

ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels: Parts A and B ◽

10.1115/fedsm-icnmm2010-30181 ◽

2010 ◽

Author(s):

Leslie Y. Yeo ◽

James R. Friend

Keyword(s):

Acoustic Waves ◽

Substrate Surface ◽

Surface Acoustic Waves ◽

Nanoparticle Synthesis ◽

Fluid Flows ◽

The Body ◽

Acoustic Energy ◽

Liquid Jets ◽

Micron Diameter ◽

Drop Interface

Though uncommon in most microfluidic systems due to the dominance of viscous and capillary stresses, it is possible to drive microscale fluid flows with considerable inertia using surface acoustic waves (SAWs), which are nanometer order amplitude electro-elastic waves that can be generated on a piezoelectric substrate. Due to the confinement of the acoustic energy to a thin localized region along the substrate surface and its subsequent leakage into the body of liquid with which the substrate comes into contact, SAWs are an extremely efficient mechanism for driving fast microfluidics. We demonstrate that it is possible to generate a variety of efficient microfluidic flows using the SAW. For example, the SAWs can be exploited to pump liquids in microchannels or to translate free droplets typically one or two orders of magnitude faster than conventional electroosmotic or electrowetting technology. In addition, it is possible to drive strong microcentrifugation for micromixing and bioparticle concentration or separation. In the latter, rich and complex colloidal pattern formation dynamics have also been observed. At large input powers, the SAW is a powerful means for the generation of jets and atomized aerosol droplets through rapid destabilization of the parent drop interface. In the former, slender liquid jets that persist up to centimeters in length can be generated without requiring nozzles or orifices. In the latter, a monodispersed distribution of 1–10 micron diameter aerosol droplets is obtained, which can be exploited for drug delivery and encapsulation, nanoparticle synthesis, and template-free polymer array patterning.

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Modeling Development of a High-Sensitivity Escherichia coli O157:H7 Detection Based on SH SAW Sensor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.925.595 ◽

2014 ◽

Vol 925 ◽

pp. 595-599

Author(s):

Seng Teik Ten ◽

Uda Hashim ◽

Ahmad Sudin ◽

Wei Wen Liu ◽

Kai Loong Foo ◽

...

Keyword(s):

Acoustic Waves ◽

High Performance ◽

Surface Acoustic Waves ◽

Equivalent Circuit Model ◽

High Sensitivity ◽

Theoretical Models ◽

Acoustic Energy ◽

Sensitive Detection ◽

Label Free ◽

Element Analysis

Surface acoustic waves based devices were initially developed for the telecommunication purpose such as signal filters and resonators. The acoustic energy is strongly confined on the surface of the surface acoustic waves (SAW) based devices and consequent their ultra-sensitivity to the surface perturbation. This has made SAW permits the highly sensitive detection of utterly diminutive charges on the surface. Hence, SAW based devices have been modified to be sensors. Food contamination has become critical issue and sensitive detection devices are needed urgently as small amount of harmful bacterial pathogens such as Escherichia coli (E.coli) O157:H7with the dose fewer than 100 organisms in food products or water is enough to cause serious gastrointestinal illness to human. Therefore, ultra-high sensitive, label free biosensors have been designed in this research for the low concentration E.coli detection. After the saturated development in telecommunication filed, SAW sensors were developed for gas detections and have been moving towards biological detections recently. Shear horizontal surface acoustic wave (SHSAW), one of the SAW based types is most suitable for the liquid based application as it has the advantage of acoustic energy is not being radiated into liquid. Therefore, SHSAW device has the potential to provide high-performance sensing platform in this research. There have been a lot of complicated theoretical models for the SAW devices development since 1960 as signal filters and resonators such as from delta function model, equivalent circuit model, to the current SAW models such as coupling-of-modes (COM) model, P-matrix model and finite element analysis (FEA) model. However, SHSAW device in this research is not meant for signal filter or resonators but used for surface sensing purpose, therefore the simplicity method of the modeling is presented in the paper for the E.coli detection sensor development.

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All-optical generation of surface acoustic waves in a silica optical microwire

10.1117/12.2051388 ◽

2014 ◽

Author(s):

Jean-Charles Beugnot ◽

Sylvie Lebrun ◽

Gilles Pauliat ◽

Herv Maillotte ◽

Vincent Laude ◽

...

Keyword(s):

Acoustic Waves ◽

Surface Acoustic Waves ◽

Optical Generation ◽

All Optical

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Design Development of Acoustic Waves Based Sensitive Sensors for Escherichia coli O157:H7 Detection

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.925.590 ◽

2014 ◽

Vol 925 ◽

pp. 590-594 ◽

Cited By ~ 1

Author(s):

Seng Teik Ten ◽

Uda Hashim ◽

Ahmad Sudin ◽

Wei Wen Liu ◽

Kai Loong Foo ◽

...

Keyword(s):

Escherichia Coli ◽

Acoustic Waves ◽

Low Cost ◽

Wave Length ◽

Surface Acoustic Waves ◽

High Volume ◽

Acoustic Energy ◽

Label Free ◽

Design Development ◽

Fecal Matter

Food contamination has become critical issue and is being worse due to the insensitive detection devices. One of the dangerous food contaminations is by Escherichia coli (E.coli) O157:H7, one of the harmful bacterial pathogens which is distributed in soil, marine and estuarine waters, the intestinal tract of animals, or water contaminated with fecal matter. A small amount of E.coli with the dose fewer than 100 organisms in food products or water is enough to cause serious gastrointestinal illness to human. Hence, the ultra-high sensitive, label free biosensors have been designed in this research for the low concentration E.coli detection. Surface acoustic waves (SAW) devices have been initially developed and used for the high-volume low-cost TV component. Due to the ultra-sensitivity to the surface perturbation, SAW based devices have been modified to be sensors. Initially, SAW sensors were developed for gas detections and have been moving towards biological detections recently. Shear horizontal surface acoustic wave (SHSAW), one of the SAW based types is most suitable for the liquid based application as it has the advantage of acoustic energy is not being radiated into liquid. However, the main SHSAW design components are the operating frequency and wave length. These are strictly depended on the inter digital transducers (IDTs) design. Therefore, this paper is presenting the IDTs design concept and pattern development by using computer aid design (CAD) software.

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Evaluation of Surface Defects Using Surface Acoustic Waves Generated by Phase Velocity Scanning of Laser Interference Fringes

Japanese Journal of Applied Physics ◽

10.1143/jjap.35.3066 ◽

1996 ◽

Vol 35 (Part 1, No. 5B) ◽

pp. 3066-3069 ◽

Cited By ~ 3

Author(s):

Harumichi Sato ◽

Hideo Cho ◽

Hideo Nishino ◽

Hisato Ogiso ◽

Kazushi Yamanaka

Keyword(s):

Phase Velocity ◽

Acoustic Waves ◽

Surface Defects ◽

Surface Acoustic Waves ◽

Laser Interference ◽

Interference Fringes

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Precise Determination of Thin Metal Film Thickness With Laser-Induced Acoustic Grating Technique

MRS Proceedings ◽

10.1557/proc-591-195 ◽

1999 ◽

Vol 591 ◽

Cited By ~ 3

Author(s):

A.A. Maznev ◽

M.J. Banet ◽

M. Gostein ◽

R.B. Hanselman ◽

M.A. Joffe ◽

...

Keyword(s):

Film Thickness ◽

Integrated Circuit ◽

Acoustic Waves ◽

Metal Film ◽

Surface Acoustic Waves ◽

Precise Determination ◽

Thin Metal Film ◽

All Optical ◽

Nondestructive Measurements

ABSTRACTAn all-optical technique based on laser excitation and detection of surface acoustic waves is capable of precise, fast, noncontact and nondestructive measurements of metal film thickness. The technique is integrated into a compact and robust instrument. Applications to metal interconnect process control in integrated circuit technology are presented.

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Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114050 ◽

1975 ◽

Vol 33 ◽

pp. 86-87

Author(s):

Kemining W. Yeh ◽

Richard S. Muller ◽

Wei-Kuo Wu ◽

Jack Washburn

Keyword(s):

Integrated Circuit ◽

Acoustic Waves ◽

New Technology ◽

Surface Acoustic Waves ◽

Electromechanical Properties ◽

Leading Role ◽

Saw Devices ◽

Transmission Electron ◽

High Degree

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.

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