2006 Fiscal Year Final Research Report Summary
Development and application of high sensitivity ultrasonic transducer for operating in air by piezo-electric polymer.
| Project/Area Number |
17560041
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied physics, general
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| Research Institution | Yamagata University |
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Principal Investigator |
TAKAHASHI Sadayuki Yamagata University, Faculty of Education, Technical Staff, 地域教育文化学部, 技術専門職員 (10396559)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Piezoelectric polymer / Ultrasonics in air / High frequency / Transducer / Acoustic imaging / TrFE) |
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| Research Abstract |
A reflection acoustic microscope system of amplitude ultrasonic wave and phase difference working in air was developed using a focused transducer made of piezoelectric polymer films of poly(vinylidene fluoride/tri-fluoroethylene) [P(VDF/TrFE)]. This transducer has an angle of aperture of 137° and a focal length of 10mm. The amplitude acoustic image was obtained at 2MHz. The transverse resolution of the amplitude image was about 150μm. Further, the phase difference resolution was about 22 μm, for which a ruggedness surface of a paper currency bill (scanning size 10 × 25mm) was able to be confirmed. In addition, we measured the acoustic velocity and absorption of a silicone-rubber plate (3mm-thinness) with a trough-transmission ultrasonic system using two planner type transducers. These values were 951 m/s and 4.5 dB/cm, respectively. These transducers have an electrode which is connected on three parallel (parallel-type) P(VDF/TrFE) films of 95μm film thickness. The insertion loss of the planner type transducers (transmitter/receiver) decreased about 15dB compared with the theoretical value estimated using Mason's equivalent circuit. This problem of attenuation of the transducer-loss is an influence of bonding. However, the present study proved that, owing to its low acoustic impedance and flexibility, the P(VDF/TrFE) piezoelectric film is very useful for high frequency acoustic imaging in air in the MHz range.
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