Mike Thompson has designed a lantern powered entirely by algae.All you have to do is add water from time to time.
From Mike Thompson:
In 2010, scientists from Yansei and Stanford University pioneered a technique by where 30-nanometre wide gold electrodes were inserted into the photosynthesising organs – chloroplasts – of algal cells, thus managing to draw a small electrical current from algae during photosynthesis. As advances in nanotechnology lead to increasingly energy efficient products, plant life such as algae will become attractive sources for tapping energy. Latro is one such product that responds to this future market.
Latro (latin for thief) incorporates the natural energy potential of algae and the functionality of a hanging lamp into its design. Synthesising both nature and technology in one form, Latro is a living, breathing product. Algae are incredibly easy to cultivate, requiring only sunlight, carbon dioxide (CO2) and water, offering a remarkably simple way of producing energy. Breathing into the handle of the lamp provides the algae with CO2, whilst the side spout allows the addition of water and release of oxygen. Placing the lamp outside in the daylight, the algae use sunlight to synthesize foods from CO2 and water. A light sensor monitors the light intensity, only permitting the leeching of electrons when the lux level passes the threshold – avoiding algae malnourishment. Energy is subsequently stored in a battery ready to be called upon during hours of darkness. Owners of Latro are required to treat the algae like a pet – feeding and caring for the algae rewarding them with light.