"It turns out these delicious little things contain everything we need to make a simple solar cell," said Blake Farrow, a Canadian scientist who filmed the video while visiting Prashant Kamat’s lab at the University of Notre Dame.
Powdered sugar contains titanium dioxide nanoparticles, a substance that is also used in paint. When that powder is coated with an organic dye, like the colorful chemicals in pasionfruit tea, it can be used as the light-absorbing layer of a photovoltaic device.
"In dye-sensitized solar cells, colored materials like tea absorb some visible light and transfer the energy to good electron transporting materials, like white TiO2, that cannot absorb on their own," said Farrow.
Once those electrons have been excited, they need somewhere to go. So Farrow sandwiched the TiO2
between a clear electrode, and a graphite electrode that he fashioned by rubbing a pencil onto some glass. As a finishing touch, he added some electrolyte solution, improvised from everclear and iodine water purification tablets.
Dye-sensitized solar cells are cheaper and more durable than traditional photovoltaics, but they are less efficient. And by extracting the titanium dioxide from donuts, Farrow gives them a whole new layer of inefficiency.Rowe, Aaron. "How to Make a Sollar Cell with donuts and Tea". Wired Science. (marzo 18, 2009). 5/Octubre/2011.Disponible en http://www.wired.com/wiredscience/2009/03/donutsolar/
Maximiliano De La Higuera Macías