Forget everything you think you know about solar cells. I’m about to tell you how visitors to Aalto University’s Multidisciplinary Institute of Digitalisation and Energy (MIDE) recent Demo Day in Espoo, Finland, made solar cells out of frozen blueberries. That’s right – blueberries. The event showcased products developed in 14 MIDE research projects investigating the use of LED technology in hybrid car parts and assistive devices for the elderly.
MIDE’s Carbon Nanobud-based Energy for Mobile Devices (CNB-E) research project focuses on developing energy production and storage technologies for mobile devices using a new material called carbon “nanobuds.” A carbon nanobud is a single-walled carbon nanotube with “fullerene” molecules (or, tiny buckyballs, for all of us non-chemists) attached to its surface. The goal of the project is to demonstrate whether carbon nanotubes and buds can be used to improve the properties of a solar cell or fuel cell.
The CNB-E demonstration gave visitors the opportunity to build a solar cell using carbon nanobuds and frozen blueberries. According to project researcher Antti Kaskela, the blueberries function as a dye sensitizer to charge the fuel cell. Dye-sensitized solar cells are a unique class of solar technology that utilize, in most cases, a synthetic dye to convert sunlight into electricity. The complex electro-chemical process is similar to photosynthesis, but produces electricity instead of starch. Compared to silicon-based colar cells, dye-sensitized solar cells are transparent, meaning they have great potential to be used aesthetically in building-integrated applications, such as solar windows.
Other featured projects at Demo Day included the E-wood project demo, which used an electron microscope to introduce visitors to energy-efficient wood processing; and the HighLight project, which demonstrated how phosphorus can be used to achieve 100 percent efficiency in LEDs.