Next Article in Journal
Exploration of Cutting Processing Mode of Low-Rigidity Parts for Intelligent Manufacturing
Previous Article in Journal
VSG-FC: A Combined Virtual Sample Generation and Feature Construction Model for Effective Prediction of Surface Roughness in Polishing Processes
Previous Article in Special Issue
Analysis of Collapse–Snapback Phenomena in Capacitive Micromachined Ultrasound Transducers
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Article

Multiple Ring Electrode-Based PMUT with Tunable Deflections

1
Laboratory for Electrical Instrumentation and Embedded Systems, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg, Germany
2
BrainLinks-BrainTools, 79110 Freiburg im Breisgau, Germany
*
Author to whom correspondence should be addressed.
Micromachines 2025, 16(6), 623; https://doi.org/10.3390/mi16060623
Submission received: 11 April 2025 / Revised: 7 May 2025 / Accepted: 22 May 2025 / Published: 25 May 2025
(This article belongs to the Special Issue MEMS Ultrasonic Transducers)

Abstract

Ultrasonic applications such as non-destructive testing, biomedical imaging or range measurements are currently based on piezoelectric bulk transducers. Yet, these kinds of transducers with their mm to cm dimensions are rather impractical in fields in which both frequencies in the kHz region and small-feature sizes are required. This fact mainly relates to the inverse relationship between the resonance frequency constant and the transducers’ dimension, yielding a higher frequency and attenuation with a decreasing size. Piezoelectric micromachined ultrasonic transducers (PMUTs), in comparison, incorporate a small-scale µm design while preserving the operating frequency in the desired kHz range. This contribution presents the detailed manufacturing of such a PMUT with a multiple ring electrode‑based structure to additionally adjust the sound pressure fields. The PMUT will be characterized by its deflection in air along with the characterization of the piezoelectric material lead zirconate titanate (PZT) itself. The measurements showed a maximum polarization of 21.8 µC/cm2 at 50 kV/cm, the PMUT’s displacement of 30.50 nm/V in air when all electrodes are driven, and an adjustable deflection via different electrode excitations without the need for additional hardware. The ring design also offered the possibility to emit two distinct frequencies simultaneously. These results demonstrate the potential of the designs for small-feature-size applications as they are in high demand for implantable devices, miniaturized ultrasonic-based communication or drug delivery.
Keywords: adjustable deflection; characterization of piezoelectric materials; multiple electrode design; PMUT; PZT annealing; ultrasonic transducers adjustable deflection; characterization of piezoelectric materials; multiple electrode design; PMUT; PZT annealing; ultrasonic transducers

Share and Cite

MDPI and ACS Style

Helmerich, J.; Wich, M.; Hofmann, A.; Schaechtle, T.; Rupitsch, S.J. Multiple Ring Electrode-Based PMUT with Tunable Deflections. Micromachines 2025, 16, 623. https://doi.org/10.3390/mi16060623

AMA Style

Helmerich J, Wich M, Hofmann A, Schaechtle T, Rupitsch SJ. Multiple Ring Electrode-Based PMUT with Tunable Deflections. Micromachines. 2025; 16(6):623. https://doi.org/10.3390/mi16060623

Chicago/Turabian Style

Helmerich, Jan, Manfred Wich, Annika Hofmann, Thomas Schaechtle, and Stefan Johann Rupitsch. 2025. "Multiple Ring Electrode-Based PMUT with Tunable Deflections" Micromachines 16, no. 6: 623. https://doi.org/10.3390/mi16060623

APA Style

Helmerich, J., Wich, M., Hofmann, A., Schaechtle, T., & Rupitsch, S. J. (2025). Multiple Ring Electrode-Based PMUT with Tunable Deflections. Micromachines, 16(6), 623. https://doi.org/10.3390/mi16060623

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop