Scientists in the United Kingdom are using spinach leaves and carrots to investigate selective formation of metallic nanoparticles in plastics. The researchers are working to form conductive circuits and create antimicrobial surfaces by accelerating the production of metals already embedded in treated plastic materials using chemicals from the plants. If successful, the practical applications include smart prosthetics, medical devices for hospitals, mobile phones, and other ‘smart’ surfaces.
The research project, known as Photobioform II, is being led by scientists from Heriot-Watt University in Edinburgh, Scotland in collaboration with researchers from the University of Leeds in England, and support from manufacturers. Photobioform II was awarded just over £350,000 under its ‘Manufacturing with Light’ Programme by the Engineering and Physical Sciences Research Council (EPSRC).
“Selective formation of metallic nanoparticles in plastics has a wide range of uses including the generation of conductive tracks for electronics interconnections and the fabrication of sensors and actuators,” explained Marc Desmulliez, the Heriot-Watt University professor leading the project.
“The use of spinach leaves or carrot extracts is a clear example of the importance of green chemistry for sustainable, low-cost and environmentally friendly manufacturing.”
The research team has found that green chemical complexes extracted from spinach leaves provide substantial reduction of light exposure compared to synthetic chemical agents. They aim “to develop bio-inspired, industrially relevant manufacturing processes that can selectively pattern metals onto non-conductive substrates using light-harvesting complexes to accelerate the reduction of metal ions embedded into substrates,” such as plastics.
The project could have major implications, such as improved functionality for limb prosthetics and microsystems for smaller mobile phones, printed electronics and wearable technology. With approximately 5,000 to 6,000 limb amputations occurring each year in the UK – and an estimated 1 million per year globally – improvements in the manufacturing of prosthetics could mean custom solutions for patients, helping thousands achieve better quality of life and improved rehabilitation times.
Besides devices, the research could also lead to state-of-the-art antimicrobial coatings that could facilitate the creation of cheaper, more reliable ways to improve sanitation in developing countries by creating bacteria-resistant coatings for three dimensional surfaces such as pipes. Such coatings may be able to eliminate micro-organisms that currently cause illnesses and diarrhoeal disease, which kills over 750,000 children each year.
“This method that could be implemented by any country with minimum amount of equipment, is another example of the power of bio-inspired manufacturing.” Desmulliez said.