Abstract
Capacitive micromachined ultrasonic transducers (CMUTs) with substrate-embedded springs offer highly efficient output pressure performance over conventional CMUTs, owing to their nonflexural parallel plate movement. The embedded silicon springs support thick Si piston plates, creating a large nonflexural average volume displacement efficiency in the operating frequency range from 1–3 MHz. Static and dynamic volume displacements of the nonflexural parallel plates were examined using white light interferometry and laser Doppler vibrometry. In addition, an output pressure measurement in immersion was performed using a hydrophone. The device showed a maximum transmission efficiency of 21 kPa/V, and an average volume displacement efficiency of 1.1 nm/V at 1.85 MHz with a low DC bias voltage of 55 V. The device element outperformed the lead zirconate titanate (PZT) ceramic HD3203, in the maximum transmission efficiency or the average volume displacement efficiency by 1.35 times. Furthermore, its average volume displacement efficiency reached almost 80% of the ideal state-of-the-art single-crystal relaxor ferroelectric materials PMN-0.33PT. Additionally, we confirmed that high-efficiency output pressure could be generated from the CMUT device, by quantitatively comparing the hydrophone measurement of a commercial PZT transducer.
Highlights
Capacitive micromachined ultrasonic transducers (CMUTs), are microelectromechanical system devices that make use of electrostatic actuation and detection of ultrasound, using multiple top moving plate geometries separated from the supportive substrate by vacuum gaps
Because CMUTs offer the advantages of improved fractional bandwidth (FBW), large operating frequency range, ease of fabrication from very small to large arrays with individual electrical connections, and simple integration with electronics, it has been proven through many demonstrations that this technology is one of the best candidates for advancing the state-of-the-art in medical ultrasound imaging [1]
Has received attention for the past two decades due to its versatility and the has received attention for the past two decades due its versatility and advantages for medical applications, some basic improvements are necessary totofurther enhance its advantages for medical applications, some basic improvements are necessary to further enhance its performance compared to piezoelectric transducers
Summary
Capacitive micromachined ultrasonic transducers (CMUTs), are microelectromechanical system devices that make use of electrostatic actuation and detection of ultrasound, using multiple top moving plate geometries separated from the supportive substrate by vacuum gaps. Because CMUTs offer the advantages of improved fractional bandwidth (FBW), large operating frequency range, ease of fabrication from very small to large arrays with individual electrical connections, and simple integration with electronics, it has been proven through many demonstrations that this technology is one of the best candidates for advancing the state-of-the-art in medical ultrasound imaging [1]. Sensors 2018, 18, 2520 with 2D CMUT arrays [5,6]; volumetric intracardiac imaging with miniature one-dimensional (1D). CMUT array [11];high-intensity and photoacoustic imaging with 1D lineartherapy and imaging using a single array [11]; and photoacoustic imaging with linear probes [12] are among the state-of-the-art demonstrations in medical applications. Because of its inherent transduction mechanism, performance compared to piezoelectric transducers. Because of its inherent transduction mechanism, the transduction efficiencies (transmission efficiency and receiving sensitivity) and FBW, are so the transduction efficiencies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
