title: Fabrication of capacitive acoustic resonators combining 3D printing and 2D inkjet printing techniques.
abstract: A capacitive acoustic resonator developed by combining three-dimensional (3D) printing and two-dimensional (2D) printed electronics technique is described. During this work, a patterned bottom structure with rigid backplate and cavity is fabricated directly by a 3D printing method, and then a direct write inkjet printing technique has been employed to print a silver conductive layer. A novel approach has been used to fabricate a diaphragm for the acoustic sensor as well, where the conductive layer is inkjet-printed on a pre-stressed thin organic film. After assembly, the resulting structure contains an electrically conductive diaphragm positioned at a distance from a fixed bottom electrode separated by a spacer. Measurements confirm that the transducer acts as capacitor. The deflection of the diaphragm in response to the incident acoustic single was observed by a laser Doppler vibrometer and the corresponding change of capacitance has been calculated, which is then compared with the numerical result. Observation confirms that the device performs as a resonator and provides adequate sensitivity and selectivity at its resonance frequency.
authors.affiliation: Centre Microélectronique de Provence (CMP), École Nationale Supérieure des Mines de Saint-Étienne, 13541 Gardanne, France. haque@emse.fr.
authors.forename: Rubaiyet Iftekharul
authors.initials: RI
authors.lastname: Haque
authors.affiliation: Laboratoire de Mécanique et D'Acoustique UPR7051 CNRS, 31 Chemin Josep Aiguier, 13402 Marseille, France. ogam@lma.cnrs-mrs.fr.
authors.forename: Erick
authors.initials: E
authors.lastname: Ogam
authors.affiliation: TAGSYS RFID, 13600 La Ciotat, France. christophe.loussert@tagsysrfid.com.
authors.forename: Christophe
authors.initials: C
authors.lastname: Loussert
authors.affiliation: Centre Microélectronique de Provence (CMP), École Nationale Supérieure des Mines de Saint-Étienne, 13541 Gardanne, France. benaben@emse.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Benaben
authors.affiliation: Centre Microélectronique de Provence (CMP), École Nationale Supérieure des Mines de Saint-Étienne, 13541 Gardanne, France. boddaert@emse.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Boddaert
keywords: 3D printing; acoustic transducer; inkjet printing; printed electronics; resonator