High sound pressure piezoelectric micromachined ultrasonic transducers using sputtered potassium sodium niobate
Author Information
Author(s): Xia Fan, Peng Yande, Yue Wei, Luo Mingze, Teng Megan, Chen Chun-Ming, Pala Sedat, Yu Xiaoyang, Ma Yuanzheng, Acharya Megha, Arakawa Ryuichi, Martin Lane W.
Primary Institution: Department of Mechanical Engineering, University of California, Berkeley, CA 94720 USA
Hypothesis
Can sputtered potassium sodium niobate films improve the performance of piezoelectric micromachined ultrasonic transducers?
Conclusion
The study demonstrates that KNN-based pMUTs can achieve significantly higher sound pressure levels compared to traditional materials.
Supporting Evidence
- A single KNN pMUT achieved a resonant frequency of 106.3 kHz under 4 Vp-p.
- The KNN pMUT demonstrated a high acoustic RMS sound pressure level of 105.5 dB/V at 10 cm.
- The output pressure of the KNN pMUT is 5-10 times higher than that of AlN-based pMUTs at similar frequencies.
- An array of 15x15 KNN pMUTs generated a focal pressure of around 160.3 dB RMS SPL at a distance of 15 mm.
- A single pMUT element was characterized as a loudspeaker with a resonant frequency of 22.8 kHz.
- The KNN pMUT was capable of detecting objects up to 2.82 m away in rangefinder applications.
Takeaway
This research shows that a new type of tiny speaker can make louder sounds using less power, which is great for gadgets like phones and sensors.
Methodology
The study involved testing a prototype KNN pMUT to evaluate its sound pressure levels and vibration characteristics.
Limitations
The study does not address long-term reliability or environmental sensitivity of the pMUTs.
Digital Object Identifier (DOI)
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