TY - CHAP A1 - Kupnik, Mario A1 - Ho, Min-Chieh A1 - Vaithilingam, Srikant A1 - Khuri-Yakub, Butrus T. T1 - CMUTs for air coupled ultrasound with improved bandwidth T2 - IEEE International Ultrasonics Symposium 2011, Orlando, Florida, USA, October 18-21, 2011 Y1 - 2011 SN - 978-1-4577-1252-4 SN - 978-1-4577-1253-1 SP - 592 EP - 595 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Apte, Nikhil A1 - Vaithilingam, Srikant A1 - Sarioglu, Ali Fatih A1 - Kupnik, Mario A1 - Khuri-Yakub, Butrus T. T1 - Large area 1D CMUT phased arrays for multi-modality ultrasound imaging T2 - IEEE International Ultrasonics Symposium 2011, Orlando, Florida, USA, October 18-21, 2011 Y1 - 2011 SN - 978-1-4577-1252-4 SN - 978-1-4577-1253-1 SP - 612 EP - 615 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Konetzke, Eric A1 - Rutsch, Matthias A1 - Hoffmann, Maik A1 - Unger, Alexander A1 - Golinske, René A1 - Killat, Dirk A1 - Ramadas, Sivaram Nishal A1 - Dixon, Steve A1 - Kupnik, Mario T1 - Phased array transducer for emitting 40-kHz air-coupled ultrasound without grating lobes T2 - Proceedings, IEEE International Ultrasonics Symposium (IUS), 21 Oct - 24 Oct 2015 Y1 - 2015 U6 - https://doi.org/10.1109/ULTSYM.2015.0019 PB - IEEE ER - TY - CHAP A1 - Hoffmann, Maik A1 - Unger, Alexander A1 - Jäger, Axel A1 - Kupnik, Mario T1 - Effect of transducer port cavities in invasive ultrasonic transit-time gas flowmeters T2 - IEEE International Ultrasonics Symposium, Taipeh (Taiwan), 2015 Y1 - 2015 U6 - https://doi.org/10.1109/ULTSYM.2015.0272 SP - 1 EP - 4 PB - IEEE ER - TY - CHAP A1 - Unger, Alexander A1 - Konetzke, Eric A1 - Rutsch, Matthias A1 - Hoffmann, Maik A1 - Ramadas, Sivaram Nishal A1 - Dixon, Steve A1 - Kupnik, Mario T1 - Versatile air-coupled phased array transducer for sensor applications T2 - IEEE Sensors 2015, Busan, South Korea Y1 - 2015 U6 - https://doi.org/10.1109/ICSENS.2015.7370187 SP - 1 EP - 4 PB - IEEE ER - TY - CHAP A1 - Ho, Min-Chieh A1 - Hoffmann, Maik A1 - Unger, Alexander A1 - Park, Kwan Kyu A1 - Kupnik, Mario A1 - Khuri-Yakub, Butrus T. T1 - CMUTs in Permanent Contact Operation for High Output Pressure T2 - Proceedings, ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems and ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels Y1 - 2015 SN - 978-0-7918-5690-1 U6 - https://doi.org/10.1115/IPACK2015-48733 PB - ASME CY - New York, NY ER - TY - CHAP A1 - Guseva, Anastasia A1 - Hoffmann, Maik A1 - Unger, Alexander A1 - Zulk, Silvia A1 - El Amien, Mohamed Balla A1 - Sarradj, Ennes A1 - Kupnik, Mario T1 - Ultrasonic transducer characterization in air based on an indirect acoustic radiation pressure measurement T2 - IEEE International Ultrasonics Symposium (IUS), 21–24 October 2015, Taipei, Taiwan Y1 - 2015 U6 - https://doi.org/10.1109/ULTSYM.2015.0333 SP - 1 EP - 4 PB - IEEE ER - TY - CHAP A1 - Golinske, René A1 - Hoffmann, Maik A1 - Konetzke, Eric A1 - Unger, Alexander A1 - Rutsch, Matthias A1 - Kupnik, Mario T1 - Diffraction loss calculation based on boundary element method for an air-coupled phased array T2 - Proceedings IEEE International Ultrasonics Symposium Proceedings, 2015 Y1 - 2015 U6 - https://doi.org/10.1109/ULTSYM.2015.0375 PB - IEEE ER - TY - CHAP A1 - Unger, Alexander A1 - Hoffmann, Maik A1 - Ho, Min-Chieh A1 - Park, Kwan Kyu A1 - Khuri-Yakub, Butrus T. A1 - Kupnik, Mario T1 - Finite element analysis of mechanically amplified CMUTs T2 - Proceedings, 2013 IEEE International Ultrasonics Symposium N2 - We introduce the possibility of improving a single-cell capacitive micromachined ultrasonic transducer (CMUT) for air-coupled ultrasound by simply adding a hollow conical-shaped structure (horn) on top of the CMUT plate. The main objective is to improve both transmit and receive sensitivity by lowering the center-to-average displacement ratio, which for bending plate operated devices inherently is limited. In addition, for receive mode the force generated from the impinging sound pressure wave is concentrated to the center of the plate, resulting in larger signals and, in contrast to piston-shaped plates, the horn has the advantage of only moderately increasing the modal mass of the structure. By using finite element analysis and first sound pressure measurements of our modified CMUT, we demonstrate that this idea is feasible and promising for air-coupled CMUTs operating at frequencies below 150kHz, as it has been been proven to be successful for commercially available piezoelectric - driven bending plate devices as well. Y1 - 2013 U6 - https://doi.org/10.1109/ULTSYM.2013.0074 SP - 287 EP - 290 PB - IEEE ER - TY - CHAP A1 - Hoffmann, Maik A1 - Unger, Alexander A1 - Ho, Min-Chieh A1 - Park, Kwan Kyu A1 - Khuri-Yakub, Butrus T. A1 - Kupnik, Mario T1 - Volumetric characterization of ultrasonic transducers for gas flow metering T2 - Proceedings, 2013 IEEE International Ultrasonics Symposium N2 - The design of ultrasonic gas flowmeters requires a thorough three dimensional characterization of the acoustic sound field. For large pipe flowmeters, such as used for flare gas metering, the transducers are operated at frequencies ranging from 20 kHz up to 150 kHz. Thus, in this work we use a commercially available calibrated 1/8-inch microphone, mounted on a 3D positioning system for performing volumetric measurements in a volume of up to 1x1x1 m. By using proper corrections in terms of angular and free-field response of the microphone, the measurement system is efficient and delivers around 30000 measurements in about only eight hours. The data then is visualized in form of 3D figures or various slices to extract all relevant information. The system has been used to identify non-uniform velocity profiles in capacitive micromachined ultrasonic transducers (CMUTs), operating in permanent contact mode. Further, the system can be used to investigate the effect of various acoustic boundary conditions the transducers are facing when mounted inside transducer port cavities and it can be used for general model validation purpose. Y1 - 2013 U6 - https://doi.org/10.1109/ULTSYM.2013.0336 SP - 1315 EP - 1318 PB - IEEE ER -