Design, Fabrication, and Evaluation of Multifocal Point Transducer for High-Frequency Ultrasound Applications

• Published in: Sensors (Basel, Switzerland) Vol. 19; no. 3; p. 609
• Main Authors: Nguyen, Thanh Phuoc, Truong, Nguyen Thanh Phong, Bui, Nhat Quang, Nguyen, Van Tu, Hoang, Giang, Choi, Jaeyeop, Phan, Thi Tuong Vy, Pham, Van Hiep, Kim, Byung-Gak, Oh, Junghwan
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 01-02-2019; MDPI AG
• Subjects: high-frequency applications; high-frequency ultrasound transducer; multifocal point transducer; PVDF focused transducer; ultrasonic transducer; high-frequency applications; multifocal point transducer; PVDF focused transducer; high-frequency ultrasound transducer; ultrasonic transducer
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s19030609

The present study illustrates the design, fabrication, and evaluation of a novel multifocal point (MFP) transducer based on polyvinylidene fluoride (PVDF) film for high-frequency ultrasound application. The fabricated MFP surface was press-focused using a computer numerical control (CNC) machining tool-customized multi-spherical pattern object. The multi-spherical pattern has five spherical surfaces with equal area and connected continuously to have the same energy level at focal points. Center points of these spheres are distributed in a linear pattern with 1 mm distance between each two points. The radius of these spheres increases steadily from 10 mm to 13.86 mm. The designed MFP transducer had a center frequency of 50 MHz and a -6 dB bandwidth of 68%. The wire phantom test was conducted to study and demonstrate the advantages of this novel design. The obtained results for MFP transducer revealed a significant increase (4.3 mm) of total focal zone in the near-field and far-field area compared with 0.48 mm obtained using the conventional single focal point transducer. Hence, the proposed method is promising to fabricate MFP transducers for deeper imaging depth applications.