Fabrication and characterization of 1-dimensional and 2-dimensional Capacitive Micromachined Ultrasonic Transducer (CMUT) arrays for 2-dimensional and volumetric ultrasonic imaging

Author(s):  
A.S. Ergun ◽  
C.-H. Cheng ◽  
U. Demirci ◽  
B.T. Khuri-Yakub
2016 ◽  
Vol 45 (4) ◽  
pp. 20160045
Author(s):  
X. Yuan ◽  
C. Li ◽  
H. Geng ◽  
S. Zhai ◽  
L. Xu ◽  
...  

2006 ◽  
Vol 321-323 ◽  
pp. 132-135
Author(s):  
Bong Young Ahn ◽  
Ki Bok Kim ◽  
Hae Won Park ◽  
Young Joo Kim ◽  
Yong Seok Kwak

As cMUTs (capacitive Micromachined Ultrasonic Transducer) offer numerous advantages over traditional transducers in terms of efficiency, bandwidth, and cost, they are expected to replace piezoelectric transducers in many applications. In particular, 2D-array cMUTs have aroused great interest in the medical engineering society because of their ability to materialize a true volumetric ultrasonic image. In this study, single element cMUTs with 32 x 32 and 64 x 64 cells were successfully fabricated. The diameter and thickness of the membrane are 35 and 1000 nm, respectively, with a sacrificial layer thickness of 600 nm. The electric characteristics of the fabricated cMUT were measured. Tests on the efficiencies of the cMUT in terms of wave generation and in terms of detection according to the bias and pulse voltage were performed in an air atmosphere.


Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 217
Author(s):  
Yuanyu Yu ◽  
Jiujiang Wang ◽  
Xin Liu ◽  
Sio Hang Pun ◽  
Shuang Zhang ◽  
...  

Capacitive Micromachined Ultrasonic Transducer (CMUT) is a promising ultrasonic transducer in medical diagnosis and therapeutic applications that demand a high output pressure. The concept of a CMUT with an annular embossed pattern on a membrane working in collapse mode is proposed to further improve the output pressure. To evaluate the performance of an embossed CMUT cell, both the embossed and uniform membrane CMUT cells were fabricated in the same die with a customized six-mask sacrificial release process. An annular nickel pattern with the dimension of 3 μ m × 2 μ m (width × height) was formed on a full top electrode CMUT to realize an embossed CMUT cell. Experimental characterization was carried out with optical, electrical, and acoustic instruments on the embossed and uniform CMUT cells. The embossed CMUT cell achieved 27.1% improvement of output pressure in comparison to the uniform CMUT cell biased at 170 V voltage. The fractional bandwidths of the embossed and uniform CMUT cells were 52.5% and 41.8%, respectively. It substantiated that the embossed pattern should be placed at the vibrating center of the membrane for achieving a higher output pressure. The experimental characterization indicated that the embossed CMUT cell has better operational performance than the uniform CMUT cell in collapse region.


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