Lamb wave mode-conversion based biological stimulation device
Ultrasonic excitation to a sample is provided with an apparatus including: a cylindrical ultrasonic transducer, and a plate disposed on an end of the cylindrical ultrasonic transducer. The ultrasonic transducer is configured to provide a vertical vibration in operation. A Lamb wave vibration is generated in the plate by the vertical vibration of the ultrasonic transducer. The Lamb wave vibration converges at a central region of the plate, where a sample is disposed. Alternatively, a cylindrical array of ultrasonic transducers can be used instead of a single cylindrical transducer. Such an array can be driven as a phased array for beam shaping and/or multi-focusing.
1 . An apparatus for providing an ultrasonic excitation to a sample, the apparatus comprising:
a cylindrical ultrasonic transducer;
a plate disposed on an end of the cylindrical ultrasonic transducer;
wherein the ultrasonic transducer is configured to provide a vertical vibration in operation;
wherein a Lamb wave vibration is generated in the plate by the vertical vibration of the ultrasonic transducer;
wherein the Lamb wave vibration converges at a central region of the plate, and wherein a sample is disposed at the central region of the plate.
2 . The apparatus of claim 1 , wherein a propagation speed of the Lamb wave vibration in the plate is less than a speed of sound in the sample.
3 . The apparatus of claim 1 , further comprising a sample holder configured to hold the sample in place at the central region of the plate.
4 . An apparatus for providing an ultrasonic excitation to a sample, the apparatus comprising:
two or more transducers configured as a cylindrical array;
a plate disposed on an end of the cylindrical array;
wherein the two or more ultrasonic transducers are configured to provide a vertical vibration in operation;
wherein a Lamb wave vibration is generated in the plate by the vertical vibration of the two or more ultrasonic transducers;
wherein the Lamb wave vibration converges at a central region of the plate, and wherein a sample is disposed at the central region of the plate.
5 . The apparatus of claim 4 , wherein a propagation speed of the Lamb wave vibration in the plate is less than a speed of sound in the sample.
6 . The apparatus of claim 4 , further comprising a sample holder configured to hold the sample in place at the central region of the plate.
7 . The apparatus of claim 4 , further comprising a controller configured to provide phased-array excitation of the two or more ultrasonic transducers.
8 . The apparatus of claim 7 , wherein the phased-array excitation of the two or more ultrasonic transducers is configured to provide multifocal excitation to the sample.