Harvesting solar, wind and rain energy all at once
Hybrid films are constructed by depositing an organic photovoltaic cell on a commercial PVDF film whilst hybrid fibres are developed by depositing an organic solar cell on a piezoelectric polymer fibre. When the hybrid film/fibre is subjected to mechanical vibrations from wind, rain or tide the piezoelectric part produces an electrical voltage which is converted to a constant DC voltage by a rectifier. The photovoltaic part of the hybrid film produces constant DC.
What makes this technology very attractive is the fact that the homogenous piezoelectric polymer fibre can be woven into fabric. This allows the design of flexible hybrid systems made of fibres that can conform to small and large structures, harvesting energy from multiple sources, without the dependence on only one renewable energy source such as solar, wind or rain. The hybrid fibres when knitted or weaved into wearable textiles can generate energy to power personal electronic gadgets and to power communication devices in remote areas. The materials are developed using less expensive non-ITO photovoltaic and lead-free piezoelectric polymer materials enabling more environmentally-friendly devices that can be mass produced at lower prices.
The research team behind this new device comprises of Prof Elias Siores, Director of IMRI and Director of Research of the University, Dr Tahir Shah, Dr Ravi Hadimani and Miss Derman Vatansever. The team has attracted a number of international grants including EU and international grants and published more than 300 scientific papers in various fields ranging from technical textile to microwave and magnetic materials.
Professor Siores holding a bundle of the hybrid photovoltaic-piezoelectric fibres.
When asked what the further development directions are that the team is following in order to improve the performance of these new devices, Professor Siores said: "We are currently working on improving the efficiency of the organic photovoltaic part of the hybrid cell by incorporating carbon nanotubes (CNT) to improve the transportation of electrons to the electrodes with which we can make thicker cells which can produce higher currents. In addition we are working on the development of piezoelectric materials through fundamental chemistry. Furthermore, conversion optimisation techniques via smart micro-grid technology are being developed to enable better energy yield levels."