| abstract |
Electroacoustic device comprising a body, an electrode to be electrically powered, named hot electrode, and an electrode to be electrically grounded, named ground electrode, the body comprising a piezoelectric part or the electroacoustic device further comprising a piezoelectric part different from the body, the hot electrode comprising a hot track spiralling around a spiral axis, the radial step between two consecutive coils of the hot track decreasing radially from the spiral axis, the hot electrode and the ground electrode being arranged on the piezoelectric part such as to define a wave transducer configured to generate a focalised ultrasonic vortex propagating in the body and/or, when a fluid medium is acoustically coupled with the electroacoustic device, in said fluid medium. |