Postgraduate research opportunities Acoustic Devices & Metamaterials

Directional Microphones: Acoustic signals can provide for the detection and location of acoustic sources. The problem of location is that it relies on triangulating a source using sensors which are spaced far enough apart. Miniature directional microphones have therefore been an active research topic for some time, but with little practical success. Some moths are capable of directional hearing despite sound wavelengths significantly longer than the distance between their ears. Recent work has shown that directionality for one moth it exclusively relies on the shape of the eardrum membrane itself. This PhD project will explore a new acoustic directional sensor concept inspired by the moth’s ear. This new concept provides a means to reach towards a truly wideband, miniature directional acoustic sensor.

Acoustic Metamaterials: Traditionally, to make a wall that blocks sound well, you have to make it thicker and denser, i.e. larger and heavier. However, if a lightweight, thin structure is required, then traditional techniques are no help. In order to manipulate sound on the small scale, a different approach is needed, and an exciting area of research to do this is based on acoustic metamaterials. An acoustic metamaterial’s properties are not derived from its base material properties, but are instead derived from the microscale structure of the material – its geometry and shape. The PhD project will explore the potential to create miniaturised acoustic metamaterials utilising 3D printing. The aim will be to create small metamaterials that operate at audio frequencies.