Inkjet-Printed Membrane for a Capacitive Acoustic Sensor: Development and Characterization Using Laser Vibrometer

Abstract

This paper describes the fabrication process and the method to determine the membrane tension and defects of an inkjet-printed circular diaphragm. The membrane tension is an important parameter to design and fabricate an acoustic sensor and resonator with the highest sensitivity and selectivity over a determined range of frequency. During this work, the diaphragms are fabricated by inkjet printing of conductive silver ink on pre-strained Mylar thin films, and the membrane tension is determined using the resonant frequency obtained from its measured surface velocity response to an acoustic excitation. The membrane is excited by an acoustic pressure generated by a loudspeaker, and its displacement (response) is acquired using a laser Doppler vibrometer (LDV). The response of the fabricated membrane demonstrates good correlation with the numerical result. However, the inkjet-printed membrane exhibits undesired peaks, which appeared to be due to defects at their boundaries as observed from the scanning mode of LDV.

Wave Propagation in Aluminum Honeycomb Plate and Debonding Detection Using Scanning Laser Vibrometer

“…The anisotropy of composite structures makes any interpretation of the signals, which determine defects and damages, difficult. One of the main advantages of laser-based sensing is the high control speed [ 34 ]. Currently, both one-dimensional and three-dimensional SLVs are used for impact damage detection in composite structures.…”

Additive Manufacturing (AM) Capacitive Acoustic and Ultrasonic Transducers Using a Commercial Direct Light Processing (DLP) Printer

“…After integrating multiple nano-fillers with the passive base polymer, an AM nano-composite can exhibit different properties including conductivity [8] or piezoelectricity [9]- [11], which allow the transduction of mechanical energy into electrical form. There are many reports of actuators [12], [13] and sensors [10], [14]- [17] fabricated using AM processes, however, various limitations in miniaturization [16], repeatability (defects) [16] and low sensitivity [10], [17] are also reported. This paper demonstrates a methodology for using a commercial digital light processing (DLP) printer to fabricate capacitive transducers which integrate a custom-made passive polymer with a custom-made conductive polymer.…”

Fabrication and Characterization of 3D Printed Thin Plates for Acoustic Metamaterials Applications

“…Furthermore, 3D printing software allows to create abstract shapes and to integrate the product inside other structures, for example by 3D printing a membrane inside a Helmholtz resonator. Haque et al [2] fabricated a thin silver layer on a purchased Mylar film using a inkjet 2D printer, that deposits drops of liquid material on pre-existing substrate. Previous research on 3D printing membranes relied on fusion deposition modeling [3], which deposits a filament layer by layer through a heated extruder nozzle head.…”

“…The advantages of these new stereolithography techniques can be found not only in the practical utility of fabricating a thin layer, but also in the opportunity to finely control its material. Moreover, multilayer plates made of different materials can be fabricated, paving the way of manufacturing a sensor or even an entire device in one print [1], [2]. In particular, when using polymers it is possible to choose the desired physical properties of the plate, given the vast range of different options available within the polymers Engineering [1], [5].…”