Micromachined Ultrasonic Transducers

Micromachined Ultrasonic Transducers PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Microfabricated ultrasonic transducers have been generated which operate in both liquids and gases. Air coupled through transmission of aluminum was observed for the first time using a pair of 2.3 MHz transducers. The dynamic range of the transducers was 110 dB, and the received signal had an SNR of 30 dB. Air coupled through transmission of steel and glass has also been observed. A theoretical model for the transducers has been refined and agrees well with experimental results. A robust microfabrication process has been developed and was used to generate air transducers which resonate from 2 to 12 MHz, as well as immersion transducers that operate in water from 1 to 20 MHz with a 60 dB dynamic range. Optimized immersion and air transducers have been designed and a dynamic range above 110 dB is anticipated. This development effort finds applications in hydrophones, medical ultrasound, nondestructive evaluation, ranging, flow metering, and scanning tip force sensing and lithography.

Micromachined Ultrasonic Transducers

Micromachined Ultrasonic Transducers PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Microfabricated ultrasonic transducers have been generated which operate in both liquids and gases. Air coupled through transmission of aluminum was observed for the first time using a pair of 2.3 MHz transducers. The dynamic range of the transducers was 110 dB, and the received signal had an SNR of 30 dB. Air coupled through transmission of steel and glass has also been observed. A theoretical model for the transducers has been refined and agrees well with experimental results. A robust microfabrication process has been developed and was used to generate air transducers which resonate from 2 to 12 MHz, as well as immersion transducers that operate in water from 1 to 20 MHz with a 60 dB dynamic range. Optimized immersion and air transducers have been designed and a dynamic range above 110 dB is anticipated. This development effort finds applications in hydrophones, medical ultrasound, nondestructive evaluation, ranging, flow metering, and scanning tip force sensing and lithography.

Piezoelectric and Acoustic Materials for Transducer Applications

Piezoelectric and Acoustic Materials for Transducer Applications PDF Author: Ahmad Safari
Publisher: Springer Science & Business Media
ISBN: 0387765409
Category : Technology & Engineering
Languages : en
Pages : 483

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Book Description
The book discusses the underlying physical principles of piezoelectric materials, important properties of ferroelectric/piezoelectric materials used in today’s transducer technology, and the principles used in transducer design. It provides examples of a wide range of applications of such materials along with the appertaining rationales. With contributions from distinguished researchers, this is a comprehensive reference on all the pertinent aspects of piezoelectric materials.

Micromachined Ultrasonic Transducers

Micromachined Ultrasonic Transducers PDF Author: Butrus T. Khuri-Yakub
Publisher:
ISBN: 9780387243917
Category : Medical
Languages : en
Pages : 250

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Book Description
The aim of this book is to teach the design and construction of micromachined ultrasonic transducers, an area rapidly increasing in popularity, and contrast and compare these transducers to each other and to traditional piezoelectric transducers. Micromachined ultrasonic transducers are gaining wide acceptance because of the use of silicon micromachining for their manufacture. This also enables capabilities of these transducers that outperform piezoelectric transducers and enable configurations that are practically impossible otherwise. This book teaches the principles of operations of micromachined ultrasonic transducers. The theory of their operation and the technology of their manufacturing will be discussed and compared to that of traditional piezoelectric transducers. Specific to the field of ultrasonic transducers, Micromachined Ultrasonic Transducers is directed at the communities that use ultrasound in the frequency range of kHz to many MHz for use in airborne and immersion applications.

ウィンター・ニット

ウィンター・ニット PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 64

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Book Description


Interface Engineering of Capacitive Micromachined Ultrasonic Transducers for Medical Applications

Interface Engineering of Capacitive Micromachined Ultrasonic Transducers for Medical Applications PDF Author: Der-Song Lin
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 168

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Book Description
Capacitive micromachined ultrasonic transducers (CMUTs), have been widely studied in academia and industry over the last decade. CMUTs provide many benefits over traditional piezoelectric transducers including improvement in performance through wide bandwidth, and ease of electronics integration, with the potential to batch fabricate very large 2D arrays with low-cost and high-yield. Though many aspects of CMUT technology have been studied over the years, packaging the CMUT into a fully practical system has not been thoroughly explored. Two important interfaces of packaging that this thesis explores are device encapsulation (the interface between CMUTs and patients) and full electronic integration of large scale 2D arrays (the interface between CMUTs and electronics). In the first part of the work, I investigate the requirements for the CMUT encapsulation. For medical usage, encapsulation is needed to electrically insulate the device, mechanically protect the device, and maintain transducer performance, especially the access of the ultrasound energy. While hermetic sealing can protect many other MEMS devices, CMUTs require mechanical interaction to a fluid, which makes fulfilling the previous criterion very challenging. The proposed solution is to use a viscoelastic material with the glass-transition-temperature lower than room temperature, such as Polydimethylsiloxane (PDMS), to preserve the CMUT static and dynamic performance. Experimental implementation of the encapsulated imaging CMUT arrays shows the device performance was maintained; 95 % of efficiency, 85% of the maximum output pressure, and 91% of the fractional bandwidth (FBW) can be preserved. A viscoelastic finite element model was also developed and shows the performance effects of the coating can be accurately predicted. Four designs, providing acoustic crosstalk suppression, flexible substrate, lens focusing, and blood flow monitoring using PDMS layer were also demonstrated. The second part of the work, presents contributions towards the electronic integration and packaging of large-area 2-D arrays. A very large 2D array is appealing for it can enable advanced novel imaging applications, such as a reconfigurable array, and a compression plate for breast cancer screening. With these goals in mind, I developed the first large-scale fully populated and integrated 2D CMUTs array with 32 by 192 elements. In this study, I demonstrate a flexible and reliable integration approach by successfully combining a simple UBM preparation technique and a CMUTs-interposer-ASICs sandwich design. The results show high shear strength of the UBM (26.5 g), 100% yield of the interconnections, and excellent CMUT resonance uniformity ([lowercase Sigma] = 0.02 MHz). As demonstrated, this allows for a large-scale assembly of a tile-able array by using an interposer. Interface engineering is crucial towards the development of CMUTs into a practical ultrasound system. With the advances in encapsulation technique with a viscoelastic polymer and the combination of the UBM technique to the TSV fabrication for electronics integration, a fully integrated CMUT system can be realized.

Ultrasonic Transducers

Ultrasonic Transducers PDF Author: K Nakamura
Publisher: Elsevier
ISBN: 0857096303
Category : Technology & Engineering
Languages : en
Pages : 749

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Book Description
Ultrasonic transducers are key components in sensors for distance, flow and level measurement as well as in power, biomedical and other applications of ultrasound. Ultrasonic transducers reviews recent research in the design and application of this important technology. Part one provides an overview of materials and design of ultrasonic transducers. Piezoelectricity and basic configurations are explored in depth, along with electromagnetic acoustic transducers, and the use of ceramics, thin film and single crystals in ultrasonic transducers. Part two goes on to investigate modelling and characterisation, with performance modelling, electrical evaluation, laser Doppler vibrometry and optical visualisation all considered in detail. Applications of ultrasonic transducers are the focus of part three, beginning with a review of surface acoustic wave devices and air-borne ultrasound transducers, and going on to consider ultrasonic transducers for use at high temperature and in flaw detection systems, power, biomedical and micro-scale ultrasonics, therapeutic ultrasound devices, piezoelectric and fibre optic hydrophones, and ultrasonic motors are also described. With its distinguished editor and expert team of international contributors,Ultrasonic transducers is an authoritative review of key developments for engineers and materials scientists involved in this area of technology as well as in its applications in sectors as diverse as electronics, wireless communication and medical diagnostics. Reviews recent research in the design and application of ultrasonic transducers Provides an overview of the materials and design of ultrasonic transducers, with an in-depth exploration of piezoelectricity and basic configurations Investigates modelling and characterisation, applications of ultrasonic transducers, and ultrasonic transducers for use at high temperature and in flaw detection systems

The 16th International Conference on Biomedical Engineering

The 16th International Conference on Biomedical Engineering PDF Author: James Goh
Publisher: Springer
ISBN: 9811042209
Category : Technology & Engineering
Languages : en
Pages : 135

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Book Description
This volume presents the proceedings of the 16th ICMBE held from 4th to 7th December 2016, Singapore. Topics of the proceedings include 6 tracks: BioImaging and BioSignals, Bio-Micro/Nano Technologies BioRobotics and Medical Devices, Biomaterials and Regenerative Medicine.- BioMechanics and Mechanobiology., Engineering/Synthetic Biology.

Airborne Capacitive Micromachined Ultrasonic Transducers in Dual-Backplate Technology

Airborne Capacitive Micromachined Ultrasonic Transducers in Dual-Backplate Technology PDF Author: Sebastian Anzinger
Publisher:
ISBN: 9783843951579
Category :
Languages : en
Pages : 0

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Book Description


Micromachined Ultrasound-Based Proximity Sensors

Micromachined Ultrasound-Based Proximity Sensors PDF Author: Mark R. Hornung
Publisher: Springer Science & Business Media
ISBN: 1461549973
Category : Technology & Engineering
Languages : en
Pages : 132

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Book Description
Micromachined Ultrasound-Based Proximity Sensors presents a packaged ultrasound microsystem for object detection and distance metering based on micromachined silicon transducer elements. It describes the characterization, optimization and the long-term stability of silicon membrane resonators as well as appropriate packaging for ultrasound microsystems. Micromachined Ultrasound-Based Proximity Sensors describes a cost-effective approach to the realization of a micro electro mechanical system (MEMS). The micromachined silicon transducer elements were fabricated using industrial IC technology combined with standard silicon micromachining techniques. Additionally, this approach allows the cointegration of the driving and read-out circuitry. To ensure the industrial applicability of the fabricated transducer elements intensive long-term stability and reliability tests were performed under various environmental conditions such as high temperature and humidity. Great effort was undertaken to investigate the packaging and housing of the ultrasound system, which mainly determine the success or failure of an industrial microsystem. A low-stress mounting of the transducer element minimizes thermomechanical stress influences. The developed housing not only protects the silicon chip but also improves the acoustic performance of the transducer elements. The developed ultrasound proximity sensor system can determine object distances up to 10 cm with an accuracy of better than 0.8 mm. Micromachined Ultrasound-Based Proximity Sensors will be of interest to MEMS researchers as well as those involved in solid-state sensor development.

High Frequency Piezo-Composite Micromachined Ultrasound Transducer Array Technology for Biomedical Imaging

High Frequency Piezo-Composite Micromachined Ultrasound Transducer Array Technology for Biomedical Imaging PDF Author: Xiaoning Jiang
Publisher:
ISBN: 9780791860441
Category : Technology & Engineering
Languages : en
Pages : 108

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Book Description
In this monograph, the authors reports the current advancement in high frequency piezoelectric crystal micromachined ultrasound transducers and arrays and their biomedical applications. Piezoelectric ultrasound transducers operating at high frequencies (>20 MHz) are of increasing demand in recent years for medical imaging and biological particle manipulation involved therapy. The performances of transducers greatly rely on the properties of the piezoelectric materials and transduction structures, including piezoelectric coefficient (d), electromechanical coupling coefficient (k), dielectric permittivity (e) and acoustic impedance (Z). Piezo-composite structures are preferred because of their relatively high electromechanical coupling coefficient and low acoustic impedance. A number of piezo-composite techniques have been developed, namely "dice and fill," "tape-casting," "stack and bond," "interdigital phase bonding," "laser micromachining" and "micro-molding". However, these techniques are either difficult to achieve fine features or not suitable for manufacturing of high frequency ultrasound transducers (>20 MHz). The piezo-composite micromachined ultrasound transducers (PC-MUT) technique discovered over the last 10 years or so has demonstrated high performance high frequency piezo-composite ultrasound transducers. In this monograph, piezoelectric materials used for high frequency transducers is introduced first. Next, the benefits and theory of piezo composites is presented, followed by the design criteria and fabrication methods. Biomedical applications using piezo composites micromachined ultrasound transducers (PC-MUT) and arrays will also be reported, in comparison with other ultrasound transducer techniques. The final part of this monograph describes challenges and future perspectives of this technique for biomedical applications.