High sound pressure piezoelectric micromachined ultrasonic transducers using sputtered potassium sodium niobate  

作　　者：Fan Xia Yande Peng Wei Yue Mingze Luo Megan Teng Chun-Ming Chen Sedat Pala Xiaoyang Yu Yuanzheng Ma Megha Acharya Ryuichi Arakawa Lane W.Martin Liwei Lin 

机构地区：[1]Department of Mechanical Engineering,University of California,Berkeley,CA 94720,USA [2]School of Electronic Science and Engineering,Southeast University,Nanjing,Jiangsu 210096,China [3]Bioengineering and Biomedical Engineering,Xi’an Jiaotong University,Xi’an,Shaanxi 710049,China [4]Tsinghua Shenzhen International Graduate School,Tsinghua University,Shenzhen 518055,China [5]Department of Materials Science and Engineering,University of California,Berkeley,CA 94720,USA [6]Scientific Research Laboratory Div.,Niterra Co.,Ltd,Nagoya 461-0005,Japan [7]Departments of Materials Science and NanoEngineering,Chemistry,and Physics and Astronomy and the Rice Advanced Materials Institute,Rice University,Houston,TX 77005,USA

出　　处：《Microsystems & Nanoengineering》2024年第6期311-323,共13页微系统与纳米工程(英文)

基　　金：supported in part by BSAC(Berkeley Sensor and Actuator Center)and the NSF grant ECCS-2128311.

摘　　要：This work presents air-coupled piezoelectric micromachined ultrasonic transducers(pMUTs)with high sound pressure level(SPL)under low-driving voltages by utilizing sputtered potassium sodium niobate K0.34Na0.66NbO3(KNN)films.A prototype single KNN pMUT has been tested to show a resonant frequency at 106.3 kHz under 4 Vp-p with outstanding characteristics:(1)a large vibration amplitude of 3.74μm/V,and(2)a high acoustic root mean square(RMS)sound pressure level of 105.5 dB/V at 10 cm,which is 5–10 times higher than those of AlN-based pMUTs at a similar frequency.There are various potential sensing and actuating applications,such as fingerprint sensing,touch point,and gesture recognition.In this work,we present demonstrations in three fields:haptics,loudspeakers,and rangefinders.For haptics,an array of 15×15 KNN pMUTs is used as a non-contact actuator to provide a focal pressure of around 160.3 dB RMS SPL at a distance of 15 mm.This represents the highest output pressure achieved by an airborne pMUT for haptic sensation on human palms.When used as a loudspeaker,a single pMUT element with a resonant frequency close to the audible range at 22.8 kHz is characterized.It is shown to be able to generate a uniform acoustic output with an amplitude modulation scheme.In the rangefinder application,pulse-echo measurements using a single pMUT element demonstrate good transceiving results,capable of detecting objects up to 2.82 m away.As such,this new class of high-SPL and low-driving-voltage pMUTs could be further extended to other applications requiring high acoustic pressure and a small form factor.

关 键 词：POTASSIUM PIEZOELECTRIC SOUND 

分 类 号：O42[理学—声学]