Electrochemical Transducers – A New Approach to Ultrasound Sensor Design

We present a study investigating the electrochemical interface as a capacitive transducer for ultrasound sensor applications. The concept is demonstrated using a nanoporous Au layer as a sensing electrode. The sensing electrode was produced by dealloying of the Ag0.8Au0.2 bulk electrode yielding an Au layer with extremely high surface/volume ratio. This electrode configuration was tested against the state of the art piezoelectric sensor subjected to electrolyte excitation with ultrasound waves having 40 kHz frequency and 4000 Pa amplitude. Our results demonstrate that nanoporous Au layer can be used as a capacitive transducer for sensing dynamic changes of pressure in electrolytes (ultrasound sensing). The sensitivity of this electrode can be readily adjusted by increasing the thickness of the dealloyed electrode layer. The transducer equation is developed and its practical relevance is discussed for electrochemical ultrasound sensor design. * The Electrochemical Society Active Member † Stanko.Brankovic@ mail.uh.edu ECS Transactions, 11 (16) 15-23 (2008) 10.1149/1.2890238 © The Electrochemical Society