Zinc oxide (ZnO) has been widely analysed as promising semiconductor material for high performance acoustic wave sensors and micro-fluidics for applications, comprising lab-on-chip, environmental monitoring, human-health monitoring & care, structural-health monitoring (SHM) and non-destructive testing (NDT). The benefits of ZnO technology developed by the Institute of Thin Films, Sensors and Imaging (ITFSI) and Novosound (academic and industrial partners, respectively, in this PhD project) include low-cost, rapid fabrication time, and high acoustic resolution In this project, the successful candidate will investigate an advanced technique known as glancing angle deposition (GLAD) to carry out the plasma deposition of ZnO nanostructured thin films, controlling inclined angle of the resulting crystalline structure, aiming to add additional capabilities to current ultrasonic sensing and imaging technology. To that end, the successful candidate will have access to both ITFSI and Novosound facilities (plasma deposition techniques, micro-fabrication tools in clean-room environment, and standard material characterisation techniques) and will be supported by a team of experts with more than 15 years' experience in the field of Physics, Material Sciences and Ultrasonic Devices.
The Institute of Thin Films, Sensors & Imaging (ITFSI), within the School of Engineering, Computing and Physical Sciences (CEPS) at the University of the West of Scotland (UWS), is a centre of excellence and key laboratory in the UK for the development of thin film technology and related applications in sensors (non-dispersive infra-red & photoacoustic) and imaging systems (hyperspectral and thin film ultrasonic imaging). UWS has made significant recent investments to the value of £12m in state-of-the-art thin film fabrication facilities within the institute. ITFSI is a world-leading research institute with its multi-disciplinary research comprising Physics, Chemistry and Engineering.
Novosound was founded in April 2018 by Dr Dave Hughes, CTO, and Richard Cooper, CEO, emerging as the first spin-out company from the University of the West of Scotland. After raising £1.5 million at its initial seed round, Novosound secured a £1m grant from Scottish Enterprise in July 2019 followed by a Series-A £3.3 million funding round in December 2019, led by Foresight Williams. In just two years, Novosound has rapidly revolutionised ultrasound technology, which has remained largely unchanged for 40 years, by replacing conventional sensor materials with a flexible piezoelectric thin-film material. Novosound has created the world’s first truly flexible NDT ultrasound tool that simplifies complex inspections in Aerospace and Energy, and a ‘Fit & Forget’ sensor that enables real-time monitoring of high value oil and gas assets. The truly flexible and high-resolution nature of Novosound’s thin-film technology has also enabled significant advancements in medical imaging and wearable technologies for healthcare. Novosound has grown rapidly to become a global business working across a wide range of diverse industry sectors and has received a number of awards from several leading institutions for its innovative ultrasound technology.
Introduction and project overview
The non-centrosymmetric crystalline structure of ZnO results in piezoelectric properties (generation of electricity from material deformation or vice versa) making ZnO based thin films and nanostructures to be unique for the development of enhanced ultrasonic sensing and imaging devices. In particular, ZnO acoustic wave devices using thin films oriented along the (0001) also known as c-axis in the wurtzite structure, have demonstrated potential for use as conventional ultrasonic transducers. These c-axis structures are only capable of producing longitudinal mode (L-mode) ultrasound perpendicular to the plane of the device. However, there are many applications in NDT and SHM where generating and detecting sound at different angles or in different modes, such as the shear mode (S-mode) could be advantageous. The control over the L- and S- components of the ultrasonic wave generated by a ZnO crystal could be achieved by depositing thin films with a specific inclined angle (i.e. the c-axis of the ZnO crystal is titled a certain angle with respect to the substrate surface). In this scenario, this project is an ambition investigation aiming to deposit c-axis inclined ZnO thin films on flexible substrates using GLAD to tune S and L mode acoustic waves for sensing and imaging applications.
This PhD will focus on the fabrication of conformable ultrasonic devices based on ZnO nanostructured thin films deposited by GLAD. The GLAD method proposed in this project not only has the potential to grow nanostructures with exceptional properties (i.e. high sensitivity and compatibility to flexible substrates) but also to make a novel use of plasma-assisted deposition techniques, taking benefit of the large-area and uniformity characteristics of such deposition method. The PhD student will optimise the piezoelectric coefficient (d33) of ZnO thin films as a function of the deposition conditions and resulting inclined angle in order to create materials suitable for use in commercially available sensors.
This project will be supported by the excellent research environment at Institute of Thin Films, Sensors and Imaging (TFSI) (academic host group) led by Prof. Desmond Gibson, at the University of the West of Scotland (UWS). Dr. Carlos Garcia will be the PhD supervisor in the academic host group. Further, the integration and characterisation of ZnO thin film ultrasonic sensors will be carried out at Novosound Ltd (industry host group) which has wide experience in the field of Ultrasonic Imaging and Sensing Devices. This will be carried out under the supervision of Dr. Kevin McAughey (Industry supervisor) and Dr. Dave Hughes (CTO of Novosound).
This project is available as a 3 year (36 months) full-time PhD study programme funded by CENSIS, Novosound and UWS. The fully funded studentships are worth £19,513 per year for 3 years, subject to satisfactory progress. They cover payment of tuition fees at the UK rate and an annual stipend of £15,146.
CENSIS funds industrially relevant doctoral research activity that supports advancements in sensing, imaging and the Internet of Things and brings technology in these spaces closer to market. https://censis.org.uk/2019/03/01/censis-phd-projects-2019-announced/. A variety of scholarship packages including fully funded studentships and fees only scholarships are available to deserving UK students.
- BS in Physics, Chemistry or Engineering, holding an honours degree 2:1 (or equivalent).
- Funded PhD Project (UK, EU and international students – fees are assumed to be that of UK student, additional fees for EU and international students are not funded by the project)
- MS in Material Sciences (or equivalent)
- Experience of applied physics (sensors, imaging, optoelectronics) and material science
- Strong mathematical background
- Experience with MATLAB, Origin, COMSOL Multiphysics, CODE, …
- Practical skills in nanotechnology (clean-room fabrication, lithography, device characterization, …)
- Experience in publishing research outcomes in conferences and journals
Research Strategy and Research Profile
This project is part of the research activity of the following Research Groups:
- Academic host: Institute of Thin Films Sensors and Imaging (ITFSI) at University of the West of Scotland (UWS) – Paisley Campus (https://www.itfsi.com/)
- Industry host: Novosound (https://www.novosound.net/)
How to Apply
If you want to join us in this ambitious project and start your research career in a unique environment provided by state-of-the-art facilities available at ITFSI and Novosound, send us your CV.
Applicants shortlisted for the PhD project will be contacted for an interview.