Cellbutton Festival took place in Yogyakarta, Indonesia, from the 15th to 23rd of July 2011. At the Solar workshop we tried to make power a small light sensitive synthesizer with DIY solar cells, gathering as much material as possible on the spot.

http://www.natural-fiber.com/cellsbutton/
 

materials used for the cells: hibiscus tea, curcuma, ethanol, candle, conductive glass, TiO2, glue
main synthesizer parts: light resistors, IRF 510 MOSFET Transistor, 40106 Hex Inverter inverter, TPA6101A2D amp chip

soldering the synth, the scheme found bellow: