Over two-thirds of the energy in the fuel you put into your car is wasted, most of it in the form of heat that exits along the exhaust pipe. The same is true of large-scale power stations, which are only 50% efficient at best. But now researchers are bringing 200 year old physics to bear against the problem by developing thermoelectric generators (TEGs) that can turn waste heat into useful electricity and this week we find out how. Plus, news that disguising cancer cells as Salmonella could hold the key to producing effective anti-cancer vaccines, why the Y chromosome boosts heart attack risk,... Like this podcast? Please help us by supporting the Naked Scientists)