scholarly journals Advances in Capacitive Micromachined Ultrasonic Transducers

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 152 ◽  
Author(s):  
Kevin Brenner ◽  
Arif Ergun ◽  
Kamyar Firouzi ◽  
Morten Rasmussen ◽  
Quintin Stedman ◽  
...  
Keyword(s):  
Review Paper ◽  
Rapid Development ◽  
Ultrasonic Transducer ◽  
Ultrasonic Transducers ◽  
Imaging Systems ◽  
Future Trends ◽  
Levels Of Abstraction ◽  
Commercial Success ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Capacitive Micromachined Ultrasonic Transducer

Capacitive micromachined ultrasonic transducer (CMUT) technology has enjoyed rapid development in the last decade. Advancements both in fabrication and integration, coupled with improved modelling, has enabled CMUTs to make their way into mainstream ultrasound imaging systems and find commercial success. In this review paper, we touch upon recent advancements in CMUT technology at all levels of abstraction; modeling, fabrication, integration, and applications. Regarding applications, we discuss future trends for CMUTs and their impact within the broad field of biomedical imaging.

Design and Analysis of Capacitive Micromachined Ultrasonic Transducers Based on SU-8

2015 ◽  
Vol 645-646 ◽  
pp. 577-582 ◽  
Author(s):  
Yu Ping Li ◽  
Chang De He ◽  
Juan Ting Zhang ◽  
Jin Long Song ◽  
Wen Dong Zhang ◽  
...  
Keyword(s):  
Acoustic Impedance ◽  
Dynamic Range ◽  
Ultrasonic Transducer ◽  
High Sensitivity ◽  
Ultrasonic Field ◽  
Ultrasonic Transducers ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Structure Simulation ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
The Relationship

In this paper, a new capacitive micromachined ultrasonic transducer (CMUT) is designed by using SU-8 material, and the theory of elastic thin plate is used to deduce the relationship between the pressure and capacitance of the structure. Simulation has been done about SU-8 CMUT by finite element method software ANSYS. The deformation of CMUT under acoustic pressure, the relationship between frequency, thickness and sensitivity, as well as the acoustic impedance and reflection coefficient of SU-8 material also have been studied through the simulation. The results turn out that SU-8 has the advantages of big dynamic range, high sensitivity and small acoustic impedance, so it has broad application in the ultrasonic field.

scholarly journals PMMA-Based Wafer-Bonded Capacitive Micromachined Ultrasonic Transducer for Underwater Applications

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 319 ◽  
Author(s):  
Mansoor Ahmad ◽  
Ayhan Bozkurt ◽  
Omid Farhanieh
Keyword(s):  
Wafer Bonding ◽  
Sacrificial Layer ◽  
Ultrasonic Transducer ◽  
Center Frequency ◽  
Single Element ◽  
Element Analysis ◽  
Laboratory Equipment ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
Dry Etch

This article presents a new wafer-bonding fabrication technique for Capacitive Micromachined Ultrasonic Transducers (CMUTs) using polymethyl methacrylate (PMMA). The PMMA-based single-mask and single-dry-etch step-bonding device is much simpler, and reduces process steps and cost as compared to other wafer-bonding methods and sacrificial-layer processes. A low-temperature (< 180 ∘ C ) bonding process was carried out in a purpose-built bonding tool to minimize the involvement of expensive laboratory equipment. A single-element CMUT comprising 16 cells of 2.5 mm radius and 800 nm cavity was fabricated. The center frequency of the device was set to 200 kHz for underwater communication purposes. Characterization of the device was carried out in immersion, and results were subsequently validated with data from Finite Element Analysis (FEA). Results show the feasibility of the fabricated CMUTs as receivers for underwater applications.

Membrane Displacement Behavior of Capacitive Micromachined Ultrasonic Transducers under Static Bias

2013 ◽  
Vol 816-817 ◽  
pp. 892-896 ◽  
Author(s):  
Reshmi Maity ◽  
R.K. Thapa ◽  
S. Baishya
Keyword(s):  
Single Cell ◽  
Ultrasonic Transducer ◽  
Ultrasonic Transducers ◽  
Critical Parameters ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Suspended Membrane ◽  
Displacement Behavior ◽  
Tension Analysis ◽  
Membrane Deflection ◽  
Membrane Displacement

The present paper focuses on the theory of vibration of a circular micro-machined ultrasonic transducer to model a single cell of Capacitive Micromachined Ultrasonic Transducers (CMUTs) and it describes the displacement behavior of membrane with respect to applied static bias following Masons analysis of a suspended membrane under tension. Analysis of the critical parameters like collapse voltage and membrane deflection is made and compared with experimental results to verify the validity of the model.

Investigation of the Half Bridge and Transformer Push–Pull Pulser Topologies for Ultrasonic Transducer Excitation

2015 ◽  
Vol 24 (05) ◽  
pp. 1550062 ◽  
Author(s):  
Linas Svilainis ◽  
Vytautas Dumbrava ◽  
Andrius Chaziachmetovas
Keyword(s):  
Experimental Investigation ◽  
Ultrasonic Transducer ◽  
Electrical Power ◽  
Rectangular Pulse ◽  
Ultrasonic Transducers ◽  
Electromagnetic Acoustic Transducer ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Acoustic Transducer ◽  
Electrical Power Consumption ◽  
Transformer Output

Comparison of two high power pulser topologies is presented. Pulser design was aimed for piezoelectric transducer excitation, yet it can also be used for electromagnetic acoustic transducer (EMAT) or capacitive micromachined ultrasonic transducers (CMUTs) excitation. Pulser can produce both single rectangular pulse and trains of rectangular arbitrary duration pulses. In order to achieve the economy of the electrical power consumption and speed both high-pulling and low-pulling elements are active switches. Energy per pulse was used to evaluate the amount of energy consumed. Two topologies were selected for evaluation: transformer output push–pull topology and half bridge output. Experimental investigation results are presented.

Characterization of Nanoscale Ultrasonic Transducer Elements as Effective Acoustical Devices

2016 ◽  
Vol 860 ◽  
pp. 35-40 ◽  
Author(s):  
Reshmi Maity ◽  
Niladri Pratap Maity ◽  
R.K. Thapa ◽  
S. Baishya
Keyword(s):  
Ultrasonic Transducer ◽  
Ultrasonic Transducers ◽  
Electrode Spacing ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Non Destructive Evaluation ◽  
Electrostatic Transducers ◽  
Gap Spacing ◽  
Non Destructive ◽  
Half Decade

The generation and detection of ultrasound in air has many applications in the field of ranging, non-destructive evaluation, microscopy and the most impactful in medical imaging. Conventional designs of electrostatic transducers have large electrode spacing of 50-100 μm which reduces the sensitivity of these capacitors. In the last one and a half decade silicon micromachining is used to define capacitors with gap spacing as small as 500Å, making it possible highly efficient capacitive micromachined ultrasonic transducers (CMUTs). In this paper a CMUT element is analytically characterized and FEM simulated. The observations are compared with published experimental results and excellent agreement is found between them.

Design and Experiment of Capacitive Micromachined Ultrasonic Transducer Array for High-Frequency Underwater Imaging

2020 ◽  
Vol 13 ◽  
Author(s):  
Yuanyu Yu ◽  
Jiujiang Wang ◽  
Xin Liu ◽  
Sio Hang Pun ◽  
Weibao Qiu ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
High Frequency ◽  
Ultrasonic Transducer ◽  
Center Frequency ◽  
Design Parameters ◽  
Underwater Imaging ◽  
Release Process ◽  
Steel Wires ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
Frequency Ultrasound

Background:: Ultrasound is widely used in the applications of underwater imaging. Capacitive micromachined ultrasonic transducer (CMUT) is a promising candidate to the traditional piezoelectric ultrasonic transducer. In underwater ultrasound imaging, better resolutions can be achieved with a higher frequency ultrasound. Therefore, a CMUT array for high-frequency ultrasound imaging is proposed in this work. Methods:: Analytical methods are used to calculate the center frequency in water and the pull-in voltage for determining the operating point of CMUT. Finite element method model was developed to finalize the design parameters. The CMUT array was fabricated with a five-mask sacrificial release process. Results:: The CMUT array owned an immersed center frequency of 2.6 MHz with a 6 dB fractional bandwidth of 123 %. The pull-in voltage of the CMUT array was 85 V. An underwater imaging experiment was carried out with the target of three steel wires. Conclusion:: In this study, we have developed CMUT for high-frequency underwater imaging. The experiment showed that the CMUT can detect the steel wires with the diameter of 100 μm and the axial resolution was 0.582 mm, which is close to one wavelength of ultrasound in 2.6 MHz.

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