About the project
Principal Investigator: Professor Robert Young
Wave energy has promising technical potential to supply immense amounts of electricity. However, despite over 50 years of research, conventional wave energy conversion (WEC) has not been deployed at scale, due to its rigid and bulky structures along with complex power take-off systems, which are inefficient and require maintenance. Dielectric elastomer generators (DEGs) consist of their key functional components – soft transducers that can harvest energy from reciprocating mechanical motion and convert it into electrical power during deformation. These soft transducers comprise dielectric elastomers sandwiched between soft electrodes that can deform with the elastomers to a large strain and conduct energy harvesting. For laboratory-based demonstrators, the soft transducers have been prepared using dielectric elastomers (mostly very high bonding elastomers VHB 4905 and 4910 provided by 3M), surface-coated with commercial conductive grease (acting as the electrodes). Such material systems suffer from vulnerabilities in marine conditions. While there are several conceptual designs already for DEG-WEC, it is crucial to ensure the performance of the materials and their response to the marine environment over the typical equipment design life of 25 years. Therefore, the focus of this proposal is to address key challenges of the materials design of DEGs, including (i) novel materials engineering for soft transducers to survive in random wave conditions, (ii) standardised evaluation of properties to ensure their translation from small-scale experiments to large scale devices.
The hypothesis explored in this project is that the elastomeric transducer in DEG must be replaced by more mechanically robust material systems prepared by a different method, such as the deposition of conductive nanocomposites. The evaluation of the mechanical and electromechanical performance can therefore be conducted through ASTM standards so that the properties measured from small-scale samples can be used for upscaling.
The first half of the project is to design a preparation method to fabricate materials for DEG while ensuring robustness. The investigators will develop layer-by-layer deposition of conductive elastomer nanocomposites onto dielectric elastomer components. Such a method enables the materials to be subjected to cyclic load with stability. The second step is to test the mechanical and electromechanical properties of the prepared materials and analyse the mechanics to obtain the key factors enabling scalability of DEG applications. We will work closely with AMOG Consulting Ltd on potential performance of energy conversion of the designed material system and with Monitra Ltd (formerly HVPD Ltd) for condition monitoring of the dielectric elastomers under high voltage energisation. Selection of materials will start with silicone-based elastomers due to their stability, low modulus, high strain at break and high strength, and be functionalised with carbon nanotubes for elastomeric electrodes. This proposal will strongly reinforce the UK’s world-leading position in this industry by providing relevant stakeholders with the necessary underpinning knowledge on the DEGWEC to provide a competitive and complementary technology to existing offshore wind, which will help to realise UK’s Net-zero target.
This project has been co-funded with Wave Energy Scotland.
