FLAUT: a mutual sensitivity improvement through matched pipe, cavity and thin plate resonance

FLAUT: a mutual sensitivity improvement through matched pipe, cavity and thin plate resonance. ELEKTRIKA- Journal of Electrical Engineering, 20 (2). pp. 42-48. ISSN 0128-4428 (2021)


Electrostatic transducers promises a great potential in alternative to piezoelectric transducer based on certain advantages such as inherently wide bandwidth and good acoustic matching to air due to the membrane’s low acoustics impedance. There are two basic designs that are popular among electrostatic ultrasonic transducer developer –rigid backplate and micromachine backplate. This paper presents a methodology for improving the sensitivity of an air-coupled ultrasonic transducer by coupling the resonating thin plate, cavity and pipe in a single cell. The proposed device is termed Fluidically Amplified Ultrasonic Transducer (FLAUT) for an air-coupled application. Investigation of the concept of matched thin plate, cavity and pipe, of which the individual geometry is expected to mutually enhance one another. Analytical modelling is utilized to the matched thin plate, cavity and pipe. The analytical modelling identifies the required geometry for the FLAUT based on the matched operating resonant frequency of 25 kHz. At the end of the paper the prototype of FLAUT is presented where the device was fabricated using additive manufacturing process (3-D printing) which consist of a 50 μm Kapton thin film over a micro stereolithography designed backplate. Here aluminum is coated as the electrode utilizing the thermal evaporation process for both the Kapton film and the backplate. A laser interferometer is utilized to measure FLAUT thin plate displacement which indicates the device is running at 25 kHz fundamental mode. A 30 dB difference is also observed between the deformation velocity of the cavity active region and its surrounding.

Item Type: Article
Keywords: Ultrasonic amplification, Electrostatic ultrasonic transducer, Fluidic amplification, Capacitive ultrasonic transducers
Taxonomy: By Subject > College of Engineering > Electrical Engineering > Communication
By Subject > College of Engineering > Electrical Engineering > Electronics
Local Content Hub: Subjects > College of Engineering
Depositing User: Eza Eliana Abdul Wahid
Date Deposited: 01 Dec 2022 04:07
Last Modified: 01 Dec 2022 04:07
Related URLs:

Actions (login required)

View Item View Item