title: Capacitive micromachined ultrasonic transducer arrays as tunable acoustic metamaterials.
abstract: Capacitive Micromachined Ultrasonic Transducers (CMUTs) operating in immersion support dispersive evanescent waves due to the subwavelength periodic structure of electrostatically actuated membranes in the array. Evanescent wave characteristics also depend on the membrane resonance which is modified by the externally applied bias voltage, offering a mechanism to tune the CMUT array as an acoustic metamaterial. The dispersion and tunability characteristics are examined using a computationally efficient, mutual radiation impedance based approach to model a finite-size array and realistic parameters of variation. The simulations are verified, and tunability is demonstrated by experiments on a linear CMUT array operating in 2-12 MHz range.
authors.affiliation: George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405, USA.
authors.forename: Shane W
authors.initials: SW
authors.lastname: Lani
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250, USA.
authors.forename: M
authors.initials: M
authors.lastname: Wasequr Rashid
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hasler
authors.affiliation: George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405, USA.
authors.forename: Karim G
authors.initials: KG
authors.lastname: Sabra
authors.affiliation: George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405, USA ; School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250, USA.
authors.forename: F
authors.initials: F
authors.lastname: Levent Degertekin
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