Field-portable acoustic system for microplastics identification in the UK waters

Project Overview

Marine microplastic pollution is a critical and escalating global environmental challenge. An estimated 150 million tonnes of plastic have accumulated in the world’s oceans, with over 12 million tonnes added each year. In Scotland alone, approximately 250 tonnes of microplastics (particles <5 mm) enter the sea annually, representing about 25 trillion samples. The environmental and economic impact is immense: marine plastic pollution costs the Scottish economy at least £20 million annually and an estimated $8 billion globally.

Microplastics affect ecosystems, marine organisms, and physical environments, with organic contaminants often adsorbing to these particles. However, current methods for microplastic collection, quantification, and identification are time-consuming, labor-intensive, and reliant on costly, complex analytical techniques. Developing faster, more efficient solutions is of urgent value.

Project Aims

This PhD project proposes the design and development of an integrated, cost-effective acoustic system to extract, separate, and identify microplastics from bulk samples. The innovative system will include:

· A two-stage cavity using acoustic waves for efficient particle sorting.

· An analytical stage to identify and fingerprint microparticles quickly and accurately.

The proposed device will allow for fast sorting and identification of microplastics within seconds. It will also be cost-effective, portable, and suitable for field use.

The student will focus on the acoustic device’s design, fabrication, and performance. Microplastic behaviour under the acoustic field will be analysed. Matlab codes and finite element modelling will be developed to complement the experimental data.

The team comprises engineers, chemists (Heriot-Watt University) and biologists (University of Stirling). The members of the team have track records of working together.

Prof. Desmulliez is the head of the Smart System group, and Dr. Anne Bernassau leads research in acoustic particle sensing. Their interests include ultrasonic sensors, ultrasonic transducer fabrication, micro-fabrication, transducer arrays, acoustofluidics, acoustic particle manipulation, and piezoelectric materials.

Dr Filipe Vivela’s research focuses on the synthesis of polymer materials. He has expertise in Polymer Chemistry, Photochemistry, and Flow Chemistry. His research focuses on Advanced Materials enabled by Flow Technology, aligning with sustainability and safety goals outlined in the UN 2030 Agenda for Sustainable Development.

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, diamond saw) and characterisation facilities (network analysers, microfluidics, Schlieren imaging system). The Institute of Chemical Sciences will provide expertise and equipment in microplastics.

Any queries should be emailed to Prof. Desmulliez (m.desmulliez@hw.ac.uk) or Dr. Anne Bernassau (a.bernassau@hw.ac.uk). 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.