Future integration of silicon electronics with miniature piezoelectric ultrasonic transducers and arrays

The long-established pace of progress in semiconductor electronics, expressed by Moore's Law, has led to new opportunities in medical ultrasound imaging. Traditionally, ultrasound systems have separated the transducer array from most of the electronic instrumentation, with multicore physical cabling in between. This avoids problems with electrical power, functional density, and communication bandwidth. However, it is far from ideal in terms of cost, ergonomics, and the need to interface instrumentation and the transducer with the cable, and it causes particular difficulties with miniature devices. Given these issues, and the relatively slow progress in front-end transducer technology, integration of the transducer with electronics is certain to increase, most likely at a pace governed by financial investment, development of electronics for other applications, and the realisation of high volume ultrasound applications. This paper therefore considers motivations for increased integration, technical barriers, and relevant new techniques, particularly related to microelectromechanical systems (MEMS). Increased integration will rely on advances in integrated circuit (IC) electronics, device assembly, and microsystems engineering, with key constraints being the packaging of a system in a small volume and the power supply. System partitioning will determine where functionality will reside physically within the imaging hardware and software. This paper considers relevant recent developments in academic research and industry, with a particular focus on medical applications. IC design is important because it defines parameters such as power consumption. 45 nm ICs are now in high volume production but the present relatively small ultrasound market makes adoption difficult. Ingenuity in exploiting existing technology cost-effectively and bespoke engineering where required are likely to be important for integration of piezoelectric material with electronics technology and functionality will correspond with different layers in a device. In this paper, examples are selected from the authors' work to illustrate progress and suggest how MEMS roadmaps and application demands may relate to future systems.

[1]  Marc P.Y. Desmulliez,et al.  Progress towards the development of novel fabrication and assembly methods for the next generation of ultrasonic transducers , 2010, 3rd Electronics System Integration Technology Conference ESTC.

[2]  David Lines,et al.  Multi-Channel Ultrasound Toolbox: A Flexible Modular Approach for Real-Time , 2010 .

[3]  Rasmus Lou-Moeller,et al.  Fabrication of high-frequency pMUT arrays on silicon substrates , 2010, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[4]  H. Levine.  Medical Imaging , 2010, Annals of Biomedical Engineering.

[5]  S. Triger,et al.  Low-voltage coded excitation utilizing a miniaturized integrated ultrasound system employing piezoelectric 2-D arrays , 2010, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[6]  S. Cochran,et al.  Progress in High Resolution Ultrasound Towards In Vivo Pathology , 2010 .

[7]  Kyusun Choi,et al.  Operation of a high frequency piezoelectric ultrasound array with an application specific integrated circuit , 2009, 2009 IEEE International Ultrasonics Symposium.

[8]  Andrew B. Kahng,et al.  A power-constrained MPU roadmap for the International Technology Roadmap for Semiconductors (ITRS) , 2009, 2009 International SoC Design Conference (ISOCC).

[9]  A. Nikoozadeh,et al.  An integrated circuit with transmit beamforming flip-chip bonded to a 2-D CMUT array for 3-D ultrasound imaging , 2009, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[10]  Kyusun Choi,et al.  CMOS Ultrasound Transceiver Chip for High-Resolution Ultrasonic Imaging Systems , 2009, IEEE Transactions on Biomedical Circuits and Systems.

[11]  David Flynn,et al.  Progress towards wafer‐scale fabrication of ultrasound arrays for real‐time high‐resolution biomedical imaging , 2009 .

[12]  John Henry Sweet,et al.  Concepts and issues in piezo-on-3D silicon structures , 2009 .

[13]  John M. Girkin,et al.  Focused ultrasound for early detection of tooth decay , 2009, 2009 IEEE International Ultrasonics Symposium.

[14]  J. Bamber,et al.  Functional characterisation of high frequency arrays based on micro-moulded 1–3 piezocomposites , 2009, 2009 IEEE International Ultrasonics Symposium.

[15]  J. Bamber,et al.  1–3 piezocomposite design optimised for high frequency kerfless transducer arrays , 2009, 2009 IEEE International Ultrasonics Symposium.

[16]  D. Cumming,et al.  Piezoelectric Materials and Structures for Ultrasonic Arrays with Low Voltage Excitation , 2009 .

[17]  S Cochran,et al.  Investigation of dental samples using a 35MHz focussed ultrasound piezocomposite transducer. , 2009, Ultrasonics.

[18]  T. Ren,et al.  Key Technologies for FeRAM Backend Module , 2009 .

[19]  Xiaoning Jiang,et al.  Frequency dependent properties of high permittivity PMNT piezoelectrics for ultrasonic transducer applications , 2008, 2008 IEEE Ultrasonics Symposium.

[20]  O. Oralkan,et al.  Integration of 2D CMUT arrays with front-end electronics for volumetric ultrasound imaging , 2008, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[21]  Lei Wang,et al.  A modular FPGA-based ultrasonic array system for applications including non-destructive testing , 2008 .

[22]  R. Thomas,et al.  5F-2 Packaging and Design of Reconfigurable Arrays for Volumetric Imaging , 2007, 2007 IEEE Ultrasonics Symposium Proceedings.

[23]  R. Whatmore,et al.  SOL-GEL FABRICATION OF PZT THICK FILMS FOR MEMS , 2007 .

[24]  M. B. Assouar,et al.  STUDY OF ACOUSTICAL AND OPTICAL PROPERTIES OF ALN FILMS FOR SAW AND BAW DEVICES: CORRELATION BETWEEN THESE PROPERTIES , 2006 .

[25]  S. Cochran,et al.  P3Q-1 Ultra Precision Grinding in the Fabrication of High Frequency Piezocomposite Ultrasonic Transducers , 2006, 2006 IEEE Ultrasonics Symposium.

[26]  P. Muralt,et al.  Thick Sol-Gel PZT Film integrated in SQI-Based, Micromachined Ultrasonic Transducers , 2006, 2006 5th IEEE Conference on Sensors.

[27]  A. Barzegar,et al.  Piezoelectric micromachined ultrasonic transducers based on PZT thin films , 2005, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[28]  S. Cochran,et al.  Net-shape ceramic manufacturing as an aid to realize ultrasonic transducers for high-resolution medical imaging , 2005, IEEE Ultrasonics Symposium, 2005..

[29]  C. K. Lee,et al.  Ultrasonic thin film transducers for high-temperature NDT , 2005 .

[30]  Max Kingsley-Jones.  A GIANT AWAKENS , 2005 .

[31]  R I Kitney,et al.  Miniature ultrasonic probe construction for minimal access surgery. , 2004, Physics in medicine and biology.

[32]  G. R. Lockwood,et al.  Integrated circuit for high-frequency ultrasound annular array , 2003, Proceedings of the IEEE 2003 Custom Integrated Circuits Conference, 2003..

[33]  B. Savord,et al.  Fully sampled matrix transducer for real time 3D ultrasonic imaging , 2003, IEEE Symposium on Ultrasonics, 2003.

[34]  Wai-Kai Chen.  Memory, Microprocessor, and ASIC , 2003 .

[35]  Nicolas Ledermann,et al.  Piezoelectric micromachined transducers (PMUT's) based on PZT thin films , 2002, 2002 IEEE Ultrasonics Symposium, 2002. Proceedings..

[36]  D. Hutchins,et al.  Cost-effective and manufacturable route to the fabrication of high-density 2D micromachined ultrasonic transducer arrays and (CMOS) signal conditioning electronics on the same silicon substrate , 2001, 2001 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.01CH37263).

[37]  J. V. Hatfield,et al.  A beam-forming transmit ASIC for driving ultrasonic arrays , 2001 .

[38]  R. Bouregba,et al.  Epitaxial PZT thin films on TiOx covered Pt/MgO substrate by RF magnetron sputtering , 2001 .

[39]  J. Mehi,et al.  High frequency ultrasound imaging: from man to mouse , 2000, 2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121).

[40]  G. R. Lockwood,et al.  Integrated circuit beamformer for high frequency array , 1999, 1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027).

[41]  B. Khuri-Yakub,et al.  A surface micromachined electrostatic ultrasonic air transducer , 1996, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[42]  D. Schindel,et al.  The design and characterization of micromachined air-coupled capacitance transducers , 1995, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[43]  F. Foster,et al.  A 45 TO 55 Mhz Needle-Based Ultrasound System for Invasive Imaging , 1993 .

[44]  G. R. Lockwood,et al.  Regular ArticleA 45 to 55 MHz Needle-Based Ultrasound System for Invasive Imaging , 1993 .

[45]  W. A. Smith,et al.  The role of piezocomposites in ultrasonic transducers , 1989, Proceedings., IEEE Ultrasonics Symposium,.