Next Article in Journal
Modal Identification of Output-Only Systems of Composite Discs Using Zernike Modes and MAC
Next Article in Special Issue
Long Slender Piezo-Resistive Silicon Microprobes for Fast Measurements of Roughness and Mechanical Properties inside Micro-Holes with Diameters below 100 µm
Previous Article in Journal
Humidity Sensors with Shielding Electrode Under Interdigitated Electrode
Previous Article in Special Issue
In-Fiber Collimator-Based Fabry-Perot Interferometer with Enhanced Vibration Sensitivity
Article Menu
Issue 3 (February-1) cover image

Export Article

Open AccessArticle

A Geometrical Study on the Roof Tile-Shaped Modes in AlN-Based Piezoelectric Microcantilevers as Viscosity–Density Sensors

Microsystems, Actuators and Sensors Group, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
Electronic Engineering Department, Hijjawi Faculty for Engineering Technology, Yarmouk University, 21163 Irbid, Jordan
Chair of Micromechanics, Microfluidics/Microactuators, Faculty of Natural Sciences and Technology II, Saarland University, 66123 Saarbrücken, Germany
Author to whom correspondence should be addressed.
Sensors 2019, 19(3), 658;
Received: 31 December 2018 / Revised: 29 January 2019 / Accepted: 1 February 2019 / Published: 6 February 2019
(This article belongs to the Special Issue Cantilever Sensor)
PDF [3982 KB, uploaded 6 February 2019]


Cantilever resonators based on the roof tile-shaped modes have recently demonstrated their suitability for liquid media monitoring applications. The early studies have shown that certain combinations of dimensions and order of the mode can maximize the Q-factor, what might suggest a competition between two mechanisms of losses with different geometrical dependence. To provide more insight, a comprehensive study of the Q-factor and the resonant frequency of these modes in microcantilever resonators with lengths and widths between 250 and 3000 µm and thicknesses between 10 and 60 µm is presented. These modes can be efficiently excited by a thin piezoelectric AlN film and a properly designed top electrode layout. The electrical and optical characterization of the resonators are performed in liquid media and then their performance is evaluated in terms of quality factor and resonant frequency. A quality factor as high as 140 was measured in isopropanol for a 1000 × 900 × 10 µm3 cantilever oscillating in the 11th order roof tile-shaped mode at 4 MHz; density and viscosity resolutions of 10−6 g/mL and 10−4 mPa·s, respectively are estimated for a geometrically optimized cantilever resonating below 1 MHz. View Full-Text
Keywords: high Q-factor; liquid media; out-of-plane; piezoelectric; AlN; cantilever high Q-factor; liquid media; out-of-plane; piezoelectric; AlN; cantilever

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Ruiz-Díez, V.; Toledo, J.; Hernando-García, J.; Ababneh, A.; Seidel, H.; Sánchez-Rojas, J.L. A Geometrical Study on the Roof Tile-Shaped Modes in AlN-Based Piezoelectric Microcantilevers as Viscosity–Density Sensors. Sensors 2019, 19, 658.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top