Marine microplastic pollution is emerging as a global and critical environmental problem. It is estimated that more than 150 million tonnes have already accumulated in the world’s oceans with more than 12 million tonnes being added each year. In Scotland, about 250 tonnes of microplastics (<5mm particles) enter the sea each year, representing about 25 trillion samples. Marine plastic alone costs the Scottish economy at least £20m per annum ($8Bn globally).
Plastic pollution has massive impact in ecological, physical and economical terms. All living organisms in the seas are affected not only by the microplastics themselves but also by the organic contaminants that are adsorbed on these plastics. The small size of microplastics complicates their collection, quantification and identification in environmental samples as opposed to meso- and macroplastics. The existing methods are time-consuming, require a high labour force, and demand elaborate techniques and expensive analytical instruments. Simplifying this process will therefore be of high value.
The research proposed in this PhD is an answer to this issue.
This PhD aims to develop an integrated cost-effective acoustic system to extract, separate and identify microplastics from bulk samples. The device uses acoustic waves and will include a 2-stage configuration made of sorting cavities. An additional analytical stage will provide the acoustic fingerprint of the microparticles. This acoustic sorting chain allows the fast the sorting/identification of microplastics in a matter of seconds. It is also cost-effective and easy to transport and can thus be used in the field.
The student will focus on the design, fabrication, and performance characterisation of the acoustic device. The behaviour of the microplastics under the acoustic field will be analysed. VISUALDOCTM software will be used for design optimisation and process integration. MATLABTM codes and finite element modelling will be developed to complement the experimental data.
The team is composed of engineers (Heriot-Watt University) and biologists (Stirling University) covering the whole span of the PhD study. The members of the team have track records in working together.
Dr. Anne Bernassau currently leads research in acoustic particle manipulation and sensing. Her interests include ultrasonic sensors, ultrasonic transducers fabrication, micro-fabrication, transducer arrays, acoustofluidics, acoustic particle manipulation and piezoelectric materials.
Prof. Marc Desmulliez’s research focus is on novel manufacturing technologies, medical device manufacturing, biomimetism and nature inspired manufacturing.
Dr. Sabine Matallana-Surget’s research focus is on environmental changes and environmental biogeochemistry.
The Institute of Signals, Sensors and Systems, provides the required expertise and facilities in microsystems design (Finite Element Modelling, AutoCAD), fabrication (3D printing/ prototyping, clean room facilities, lapping/polishing machines, laser ablation, CNC machining, diamond saw) and characterisation facilities (network analysers, microfluidics, SEM, optical profilometer, Schlieren imaging system).
We are looking for candidates that already hold or are on track to graduate with First class honours degree in engineering, physics, or a related discipline. The scheme is open to UK students (national or resident ). The position is for a duration of 36 months. The start date, to be agreed, can be from September 2022.
Any queries should be sent by email to Dr. Anne Bernassau ([Email Address Removed]). Applications should consist of a single PDF including a motivation letter, CV, publication list, and names of 2 references) and be submitted via the Heriot-Watt University website.