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

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.

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 152 ◽  
Author(s):  
Kevin Brenner ◽  
Arif Ergun ◽  
Kamyar Firouzi ◽  
Morten Rasmussen ◽  
Quintin Stedman ◽  
...  

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.


2013 ◽  
Vol 816-817 ◽  
pp. 892-896 ◽  
Author(s):  
Reshmi Maity ◽  
R.K. Thapa ◽  
S. Baishya

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.


2016 ◽  
Vol 860 ◽  
pp. 35-40 ◽  
Author(s):  
Reshmi Maity ◽  
Niladri Pratap Maity ◽  
R.K. Thapa ◽  
S. Baishya

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.


2014 ◽  
Vol 493 ◽  
pp. 233-238
Author(s):  
Aries Prih Haryono ◽  
Edi Sukamto ◽  
Sumeru ◽  
Farid Nasir Ani

This study presents an experimental study on a freezer which has small cooling capacity. Typically a freezer uses primary refrigerant (direct cooling) to cool or freeze a product. In this study, a prototype of freezer using a compressor 250 W nominal power at 220V was designed and constructed. The freezer is operated on two conditions, that is, using primary and secondary refrigerant. R22 and R290 (propane) were used as primary refrigerant, whereas aqueous solution of propylene glycol as secondary refrigerant. Comparison of the system performance between the primary and the secondary refrigerant werepresented. Also, the experimental results showed that the use of R290 as primary refrigerant to replace R22 in the freezer could save electrical power consumption by 18.5%. Meanwhile, the use of the secondary refrigerant yielded energy savings by 33.19% compared with the primary refrigerant.


2015 ◽  
Vol 645-646 ◽  
pp. 577-582 ◽  
Author(s):  
Yu Ping Li ◽  
Chang De He ◽  
Juan Ting Zhang ◽  
Jin Long Song ◽  
Wen Dong Zhang ◽  
...  

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.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Kumar ◽  
Chhotu Ram ◽  
Adebabay Tazeb

AbstractEnergy conservation has become an essential step in pulp and paper industry due to diminishing fossil reserves and high cost of energy. Refining is a mechanical treatment of pulp that modifies the structure of the fibres in order to achieve desired paper-making properties. However, it consumes considerable amount of energy. The electrical power consumption has a direct impact on paper manufacturing cost. Therefore, there is a requirement to minimize the energy cost. Enzyme-assisted refining is the environment friendly option that reduces the energy consumption for papermaking. Enzyme-assisted refining is defined as mechanical refining after pretreatment of pulp with enzymes such as cellulases and hemicellulases. It not only reduces the energy consumption but also improves the quality of finished paper. Enzymes improve the beatability of pulp at same refining degree (°SR) and desired paper properties can be achieved at decreased refining time. The selection of suitable enzyme, optimization of enzyme dose and appropriate reaction time are the key factors for energy reduction and pulp quality improvement during enzyme-assisted refining.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 421
Author(s):  
Jorge Oevermann ◽  
Peter Weber ◽  
Steffen H. Tretbar

The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.


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