A thin and flexible transducer design for use in air is described. It is fabricated from three or more layers of material to form an electrostatic device with many interesting properties. The new acoustic source has an excellent high-frequency response and can be used as an acoustic radiator over a wide range of frequencies, in both the audible and ultrasonic frequency ranges. The frequency response and directivity are both modeled and compared to theory, where it is demonstrated that the device operates in a manner consistent with a plane piston source.

A theoretical approach is described which predicts the fields of acoustic radiators with a predefined surface topography. This is achieved by dividing the surface of the source into small elements, each of which is oriented parallel to the tangent to the surface at that point. The result is an improved modeling performance, in that it is more efficient and requires far fewer elements compared to other numerical approaches using parallel elements. Theoretical predictions are compared to experimental results from curved electrostatic radiators, to demonstrate that the approach has promise.

Thin and flexible electrostatic loudspeakers have been constructed, which can be curved into different shapes. This allows some interesting geometries to be explored, at frequencies in the range 10 kHz to 100 kHz. The research has compared the radiated fields measured experimentally with those predicted using established theory. The theoretical approach uses a new geometrical formulation to more efficiently predict radiated field patterns, where the curved surface is considered as a series of elements at specific angles to the beam axis. These elements can be of increased width compared to previous methods, making the approach computationally efficient. It is also a more robust approach than the traditional impulse response methods, in situations where the source size is comparable to the radiated wavelengths in air. Predictions could be made for both continuous and transient excitation. A comparison between theory and experiment has demonstrated that interesting field patterns can be generated. For instance, focussed sound fields can be produced using concave shapes, with predictable focal positions which are not at the center of curvature. These and other geometries will be described.