Electro-shoes with built-in generators that produce enough power run a laptop computer, or keep a person warm on a cold day are to go into mass production.

The "e-man" shoes, invented and built by a Croatian entrepreneur, have drawn the attention of the US military according to Croatian daily Vecernji List, and talks with other buyers are said to be at an advanced stage.

The shoes are designed to generate electricity when a person walks and then transfer that power to special clothing which converts it into heat.