Microwave Capacitive Pressure Sensor Based on an Additively Manufactured Elastic Layer
Karami-Horestani, Amirhossein (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Rodini, Sandra (Università di Pisa. Dipartimento di Ingegneria dell'Informazione)
Genovesi, Simone (Università di Pisa. Dipartimento di Ingegneria dell'Informazione)
Paredes Marco, Ferran (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Costa, Filippo (Università di Pisa. Dipartimento di Ingegneria dell'Informazione)
Martín, Ferran (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)

Date:	2024
Abstract:	This paper presents a capacitive sensor useful for measuring pressure in the range 0 Pa - 2460 Pa. The transduction mechanism is capacitance variation caused by changes in the force exerted on the sensing element. Such sensing element is a one-port coplanar waveguide (CPW) terminated with a conductive patch wider than the CPW central strip and a step impedance resonator (SIR), etched in an independent substrate and capacitively coupled to the patch. By sandwiching an additively manufactured malleable (elastic) material between the CPW and the SIR substrate, pressure changes modify the capacitance of the SIR due to the variation of (i) the dielectric constant of such material and (ii) the separation between the SIR and CPW metal layers. The output variable is the phase of the reflection coefficient at the operating frequency, set to a value (within the microwave range) where the phase response exhibits a high phase slope (since this boosts the sensitivity). Thus, the device is a single-frequency sensor that simply necessitates a microwave oscillator, or a voltage-controlled oscillator (VCO), for signal generation in operative environment. The maximum achieved sensitivity is 65°/kPa.
Grants:	Agencia Estatal de Investigación PID2022-139181OB-I00 Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-00192 Agencia Estatal de Investigación PRE2020-093239
Rights:	Aquest material està protegit per drets d'autor i/o drets afins. Podeu utilitzar aquest material en funció del que permet la legislació de drets d'autor i drets afins d'aplicació al vostre cas. Per a d'altres usos heu d'obtenir permís del(s) titular(s) de drets.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Additive manufacturing ; Coplanar waveguide (CPW) ; Microwave sensor ; Pressure sensor ; Step-impedance resonator (SIR) ; Structural health monitoring (SHM)
Published in:	IEEE sensors journal, Vol. 25, Issue 2 (January 2025) , p. 2618-2628, ISSN 1558-1748

DOI: 10.1109/JSEN.2024.3510657

Available from: 2027-01-31 Postprint

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Engineering > CIMITEC-UAB
Articles > Research articles
Articles > Published articles