A micromachined piezoelectric ultrasonic transducer operating in d 33 mode using square interdigital electrodes

Chao Wang; Zheyao Wang; Tian Ling Ren; Yiping Zhu; Yi Yang; Xiaoming Wu; Haining Wang; Huajun Fang; Litian Liu

doi:10.1109/JSEN.2007.896562

A micromachined piezoelectric ultrasonic transducer operating in d ₃₃ mode using square interdigital electrodes

Chao Wang, Zheyao Wang, Tian Ling Ren, Yiping Zhu, Yi Yang, Xiaoming Wu, Haining Wang, Huajun Fang, Litian Liu

Research output: Contribution to journal › Article › peer-review

34 Scopus citations

Abstract

This paper presents the design, fabrication, and characterization of a piezoelectric micromachined ultrasonic transducer (pMUT) operating in d ₃₃ mode. A piezoelectric PZT thin film is polarized along the in-plane direction using top square interdigital electrodes (IDEs), and the in-plane polarization and IDEs enable the pMUT to operate in d₃₃ mode, which allows the PZT to convert the ultrasonic pressure-induced in-plane stresses into in-plane direction charges. The square IDEs fully exploit the stresses of the diaphragm to improve sensitivity and increase device capacitance, and the pMUT is optimized by varying the IDE dimensions rather than the thickness of the PZT film. Theoretical and finite-element analyses are performed to optimize the diaphragm and the IDE dimensions in terms of resonance frequency and sensitivity, respectively. The ultrasonic directivity of the pMUTs with different packaging configurations is characterized, showing large ultrasound inlet areas beneficial to ultrasonic applications requiring high directivity.

Original language	English (US)
Pages (from-to)	967-975
Number of pages	9
Journal	IEEE Sensors Journal
Volume	7
Issue number	7
DOIs	https://doi.org/10.1109/JSEN.2007.896562
State	Published - Jul 2007
Externally published	Yes

Keywords

D mode
Directivity
In-plane polarization
Interdigital electrode (IDE)
PZT
Ultrasonic transducer

ASJC Scopus subject areas

Instrumentation
Electrical and Electronic Engineering

Access to Document

10.1109/JSEN.2007.896562

Cite this

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title = "A micromachined piezoelectric ultrasonic transducer operating in d 33 mode using square interdigital electrodes",

abstract = "This paper presents the design, fabrication, and characterization of a piezoelectric micromachined ultrasonic transducer (pMUT) operating in d 33 mode. A piezoelectric PZT thin film is polarized along the in-plane direction using top square interdigital electrodes (IDEs), and the in-plane polarization and IDEs enable the pMUT to operate in d33 mode, which allows the PZT to convert the ultrasonic pressure-induced in-plane stresses into in-plane direction charges. The square IDEs fully exploit the stresses of the diaphragm to improve sensitivity and increase device capacitance, and the pMUT is optimized by varying the IDE dimensions rather than the thickness of the PZT film. Theoretical and finite-element analyses are performed to optimize the diaphragm and the IDE dimensions in terms of resonance frequency and sensitivity, respectively. The ultrasonic directivity of the pMUTs with different packaging configurations is characterized, showing large ultrasound inlet areas beneficial to ultrasonic applications requiring high directivity.",

keywords = "D mode, Directivity, In-plane polarization, Interdigital electrode (IDE), PZT, Ultrasonic transducer",

author = "Chao Wang and Zheyao Wang and Ren, {Tian Ling} and Yiping Zhu and Yi Yang and Xiaoming Wu and Haining Wang and Huajun Fang and Litian Liu",

note = "Funding Information: Manuscript received October 18, 2006; revised January 8, 2007; accepted January 9, 2007. This work was supported in part by the National Natural Science Foundation of China under Grant 90407023, and “863” Program of China under Grant 2004AA404240. The associate editor coordinating the review of this paper and approving it for publication was Dr. Errol EerNisse.",

year = "2007",

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AU - Wang, Chao

AU - Wang, Zheyao

AU - Ren, Tian Ling

AU - Zhu, Yiping

AU - Yang, Yi

AU - Wu, Xiaoming

AU - Wang, Haining

AU - Fang, Huajun

AU - Liu, Litian

N1 - Funding Information: Manuscript received October 18, 2006; revised January 8, 2007; accepted January 9, 2007. This work was supported in part by the National Natural Science Foundation of China under Grant 90407023, and “863” Program of China under Grant 2004AA404240. The associate editor coordinating the review of this paper and approving it for publication was Dr. Errol EerNisse.

PY - 2007/7

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N2 - This paper presents the design, fabrication, and characterization of a piezoelectric micromachined ultrasonic transducer (pMUT) operating in d 33 mode. A piezoelectric PZT thin film is polarized along the in-plane direction using top square interdigital electrodes (IDEs), and the in-plane polarization and IDEs enable the pMUT to operate in d33 mode, which allows the PZT to convert the ultrasonic pressure-induced in-plane stresses into in-plane direction charges. The square IDEs fully exploit the stresses of the diaphragm to improve sensitivity and increase device capacitance, and the pMUT is optimized by varying the IDE dimensions rather than the thickness of the PZT film. Theoretical and finite-element analyses are performed to optimize the diaphragm and the IDE dimensions in terms of resonance frequency and sensitivity, respectively. The ultrasonic directivity of the pMUTs with different packaging configurations is characterized, showing large ultrasound inlet areas beneficial to ultrasonic applications requiring high directivity.

AB - This paper presents the design, fabrication, and characterization of a piezoelectric micromachined ultrasonic transducer (pMUT) operating in d 33 mode. A piezoelectric PZT thin film is polarized along the in-plane direction using top square interdigital electrodes (IDEs), and the in-plane polarization and IDEs enable the pMUT to operate in d33 mode, which allows the PZT to convert the ultrasonic pressure-induced in-plane stresses into in-plane direction charges. The square IDEs fully exploit the stresses of the diaphragm to improve sensitivity and increase device capacitance, and the pMUT is optimized by varying the IDE dimensions rather than the thickness of the PZT film. Theoretical and finite-element analyses are performed to optimize the diaphragm and the IDE dimensions in terms of resonance frequency and sensitivity, respectively. The ultrasonic directivity of the pMUTs with different packaging configurations is characterized, showing large ultrasound inlet areas beneficial to ultrasonic applications requiring high directivity.

KW - D mode

KW - Directivity

KW - In-plane polarization

KW - Interdigital electrode (IDE)

KW - PZT

KW - Ultrasonic transducer

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