Two billion people use open fires as their primary cooking method. These fires have been found to be highly inefficient, with 93 per cent of the energy generated lost. And when used in enclosed spaces, smoke from the fires can cause health problems.
The unit would be capable of converting heat into acoustic energy and then electricity, for around one hour’s use per kilogram of fuel. The cost target for the generator is £20 [USD33] per household.
Score Technical Targets:
– Cost: target (£20) per household in 1 million quantities, weight: 10-20kg, power
output: 150 W (electrical), 1.6 kWth for cooking and 0.75 kWth for simmering.
– Fuel: consumption 1 kg/hour, wood, dung and other bio-mass.
The contraption–a tube-like extension hooked onto the cell phone with a modified belt clip–works just like a traditional microscope, using a series of lenses that magnify blood or spit samples on a microscope slide. To detect TB, for example, a spit sample is infused with an inexpensive dye called auramine. An “excitation” wavelength is emitted by the light source–a blue light-emitting diode (LED) on the opposite end of the device from the cell phone–and absorbed by the auramine dye in the spit sample, which fluoresces green to illuminate TB bacteria.