SARAH LONG:Scientists have tried for a long time to invent a human-like machine.
Devices that can operate themselves and do some things humans can do are called robots.
Now,Stuart Wilkinson has invented a robot that can eat food.
This food is used to produce energy that the robot needs to work.
It is the first robot to be completely powered by food.It is called a gastrobot.
Mister Wilkinson works at the American University of South Florida in Tampa.
He has named his gastrobot Chew Chew.The robot has twelve legs and looks like a train.
It has three parts.Each part is a meter long.Chew Chew's stomach is a device that uses bacteria to break down food.
The bacteria,E,Coli,produce substances called enzymes,which can break down carbohydrates.
The process releases electrons that are used to power a battery.
In this way,chemical energy is used to produce electricity.Humans get energy from food in a similar way.
BOB DOUGHTY:The inventor says the gastrobot is only being fed sugar right now.
This is because the bacteria break down almost all the sugar and produce very little waste.
The only waste produced is carbon dioxide gas and water.Chew Chew can also eat vegetables.
Scientists say the first versions of such a robot could be used to cut grass,for example.
The robot could power itself with the grass it is cutting.
Mister Wilkinson hopes to improve the design of the robot so that it can feed itself.
In the future,scientists hope to invent robots that can produce enough energy to power a car or a train.
Another idea is an underwater robot that could eat fish.
Mister Wilkinson says a gastrobot eating meat would produce the most energy.
However,he says it might be dangerous to give robots their first taste of meat.
They might realize that humans are meat and can be eaten too.