The idea of re-wiring humans to make them capable of re-growing limbs sounds like an experiment from Dr Frankenstein's lab. But one scientist believes that the creepy idea could soon be a reality. Dr Michael Levin has already created a range of strange creatures, including tadpoles with eyes on their backs and frogs with six legs, and believes that in the future he will be able to re-wire humans to come in any shape desired. Dr Levin's work focusses on ion channels – hollow proteins across the surface of cells, which allow charged molecules to pass through. Within each channel, tiny gates control the flow of these molecules.