Arrangement design for horizontally omnidirectional audible sound source using facing ultrasonic transducer arrays

Abstract

We developed an audible sound source with horizontal omnidirectional patterns using facing ultrasonic transducer arrays. The arrays emitted sound with different ultrasonic frequencies from each side, and an audible sound with a differential frequency is generated between input ultrasonic signals. In particular, we designed and created a new array that can control the number of transducers driven in the array. We evaluated the frequency–amplitude characteristics and directivity when the transducers in the array were driven in an annular shape. There is an optimum array shape and number of transducers that can be driven for a specific distance between arrays.

Evaluation of transducer for cryogenic actuators by equivalent circuit model

“…[21][22][23][24] Piezoelectric actuators have the advantages of easy miniaturization and large volumetric output ratio. [25][26][27][28] The disadvantage is that the piezoelectric performance degrades as the temperature decreases, causing a reduction in vibration performance. The method of applying a preload is known to maximize the performance of piezoelectric elements.…”

Optical fiber-based acoustic intensity microphone for high-intensity airborne ultrasound measurement

“…These technologies have a wide range of applications, as evidenced by recent studies. [1][2][3][4][5] For instance, innovations such as highly directional speakers, [6][7][8] non-contact tactile feedback, [9][10][11] threedimensional acoustic levitation and manipulation, [12][13][14][15][16][17][18][19] graphics on a carpet, 20) artificial pollination, 21) insect pest control, 22) wound healing acceleration, 23) hair regrowth, 24) horizontally omnidirectional audible sound source, 25) and non-destructive testing 26) showcase the potential of high-intensity ultrasonic applications. Notably, the exploration of acoustic holography based on phased arrays has become increasingly prominent, leading to sophisticated sound field control.…”