EPSRC CDT in Metamaterials: Micro-acoustic arrays for active sound control
Prof A P Hibbins
Dr D Horsell
No more applications being accepted
Competition Funded PhD Project (European/UK Students Only)
The studentship is part of the EPSRC Centre of Doctoral Training in Metamaterials (XM2). Its aim is to undertake world-leading research, while training scientists and engineers with the relevant research skills and knowledge, and professional attributes for industry and academia.
The aim of this project is to investigate the physics behind and realisation of an active acoustic surface. This surface detects a sound wave incident upon it and, instead of simply reflecting it back or absorbing it, responds by emitting sound that mixes with the original. Such surfaces could be used to cancel, disrupt, focus or redirect the sound to achieve effects such reverberation and beaming, with applications ranging from recording studios through to medical ultrasound treatments and defence. Even in nature, bat echolocation has been shown to be ’jammed’ in this way by moths and other bats [Science 325, 325 (2009), ibid. 346, 745 (2014)].
Controllable active surfaces are composed of arrays of detectors and generators. The elements of the array can be described as ‘meta-atoms’ forming a metamaterial surface. Such meta-atoms allow control over the relative amplitude and phase of sound produced by the generators in response to an incident signal. The link between the meta-atoms is key here: to cancel an incident acoustic pulse, the electrical response of the detector would need to be fed into the generator on a sufficiently fast timescale. The project is to investigate methods to realise such arrays, including the physics of how the meta-atoms could be miniaturised, be made acoustically ‘invisible’ [Nature Communications 6, 5905 (2015)], and have amplitude gain and a broad frequency response [analogous to Appl. Phys. Lett. 99, 254103 (2011)]. It will involve both modelling and experiment, and benefit from the CDT community through analogies with optical systems.
4-year studentship: UK/EU students, includes tuition fees and an annual stipend equivalent to current Research Council rates (14,553 for 2017-18).