A compressed skins-tensioned core structure includes a first surface region; a second surface region; a core between the first surface region and the second surface region; a first transition region continuous with the first surface region at a side, and continuous with the core at another side; and a second transition region continuous with the core at a side, and continuous with the second surface region at another side, wherein each of the first surface region, the second surface region, the core, the first transition region and the second transition region is formed of a substantially homogeneous amorphous material; each of the first surface region and the second surface region exhibits an internal compressive stress, the core exhibits an internal tensile stress, and each of the first transition region and the second transition region exhibits a stress gradient from the internal compressive stress to the internal tensile stress.

An apparatus of the disclosure is directed to conical structure of an ultrasonic transducer. The conical structure may have a first circumference and a second circumference, respectively located at opposite ends of the conical structure, where the first circumference has a greater length than the second circumference. An angle may be formed between a plane including the second circumference and a surface of the conical structure, and a distance may be formed between the first and second circumferences. A rim may be coupled at or adjacent to the first circumference of the conical structure. An ultrasonic transducer may be coupled to the second circumference of the conical structure.

An apparatus of the disclosure is directed to conical structure of an ultrasonic transducer. The conical structure may have a first circumference and a second circumference, respectively located at opposite ends of the conical structure, where the first circumference has a greater length than the second circumference. An angle may be formed between a plane including the second circumference and a surface of the conical structure, and a distance may be formed between the first and second circumferences. A rim may be coupled at or adjacent to the first circumference of the conical structure. An ultrasonic transducer may be coupled to the second circumference of the conical structure.

An apparatus of the disclosure is directed to an elongated polygon transducer membrane having a perimeter that includes a plurality of edges and a plurality of vertices. The elongated polygon transducer membrane may be fixed to a support structure at or around a plurality of the vertices and not fixed to the support structure at more than 50% of the perimeter. The apparatus of the disclosure may be an elongated hexagon transducer membrane having a perimeter comprising six edges and six vertices. The elongated hexagon transducer membrane may be fixed to a support structure at or around two vertices of the six vertices that are most distant from each other and not fixed at the other vertices or the edges of the perimeter.

An apparatus of the disclosure is directed to an elongated polygon transducer membrane having a perimeter that includes a plurality of edges and a plurality of vertices. The elongated polygon transducer membrane may be fixed to a support structure at or around a plurality of the vertices and not fixed to the support structure at more than 50% of the perimeter. The apparatus of the disclosure may be an elongated hexagon transducer membrane having a perimeter comprising six edges and six vertices. The elongated hexagon transducer membrane may be fixed to a support structure at or around two vertices of the six vertices that are most distant from each other and not fixed at the other vertices or the edges of the perimeter.

An apparatus of the disclosure is directed to an elongated polygon-shaped transducer elastic layer having a first plurality of edges, a first plurality of vertices, and a first electrical connection at one of the first plurality of vertices. The apparatus includes an elongated polygon-shaped electrically active material layer having a second plurality of edges, a second plurality of vertices, and a second electrical connection at one of the second plurality of vertices, where the elongated polygon-shaped electrically active material layer is disposed on the elongated polygon-shaped transducer elastic layer to transform electrical excitation into a high-frequency vibration to produce ultrasonic acoustic emissions or transform received high-frequency acoustic vibration into electrical signals. The elongated polygon-shaped transducer elastic layer and the elongated polygon-shaped electrically active material layer may be hexagonal.

An apparatus of the disclosure is directed to an elongated polygon-shaped transducer elastic layer having a first plurality of edges, a first plurality of vertices, and a first electrical connection at one of the first plurality of vertices. The apparatus includes an elongated polygon-shaped electrically active material layer having a second plurality of edges, a second plurality of vertices, and a second electrical connection at one of the second plurality of vertices, where the elongated polygon-shaped electrically active material layer is disposed on the elongated polygon-shaped transducer elastic layer to transform electrical excitation into a high-frequency vibration to produce ultrasonic acoustic emissions or transform received high-frequency acoustic vibration into electrical signals. The elongated polygon-shaped transducer elastic layer and the elongated polygon-shaped electrically active material layer may be hexagonal.

A sound generating device includes a case and a diaphragm fixed to the inner surfaces of first to fourth side wall portions of the case via a support member. An air chamber surrounded by a top plate, the diaphragm, and portions of the first to fourth side wall portions is formed. A sound emitting chamber that extends between the air chamber and the atmosphere outside of the case terminates at a sound emitting hole which extends across a plurality of surfaces of the case 2.

A sound generating device includes a case and a diaphragm fixed to the inner surfaces of first to fourth side wall portions of the case via a support member. An air chamber surrounded by a top plate, the diaphragm, and portions of the first to fourth side wall portions is formed. A sound emitting chamber that extends between the air chamber and the atmosphere outside of the case terminates at a sound emitting hole which extends across a plurality of surfaces of the case 2.

An elastic structure between two objects, consisting of a first object provided with at least one first side, a second object provided with at least one second side, and an elastic connecting object that is connected between the first object and the second object, wherein the first side and the second side mutually correspond. The elastic connecting object is provided with a first connecting portion that connects to the first side, a second connecting portion that connects to the second side, and an elastic connecting portion that connects between the first connecting portion and the second connecting portion. Accordingly, the elastic connecting portion is provided with an elastic restoring force, which enables the second connecting portion and the first connecting portion to realize an elastic displacement function that enables achieving mutually relative up/down elastic displacement positions between the first object and the second object.