WATCH: Engineers develop army of world's smallest robots

• Made out of shape-memory alloy, the tiny robots are only half a millimetre wide. 
• They can carry out complex tasks in smaller spaces.
• Experts heat their tiny legs using a laser to bend them. 

Scientists at the Northwestern University in Illinois have developed what they are calling the smallest robots in the world.

The engineers claim that they are the tiniest remote controlled robots ever made.

Yahoo News reported that a "fleet of crab-like" robots has been developed which can carry out complex tasks in smaller spaces.

Made out of shape-memory alloy, the tiny robots are only half a millimetre wide. 

According to the team of engineers, the little crabs not only walk and crawl but have the power to bend, twist, and even jump.

“You might imagine micro-robots as agents to repair or assemble small structures or machines in industry or as surgical assistants to clear clogged arteries, to stop internal bleeding, or to eliminate cancerous tumors," said John A. Rogers, professor of materials science and engineering, biomedical engineering, and neurological surgery at Northwestern University.

The robots are so tiny they can sit on the tip of a pen. 

They do not use electronics to move. Instead, because of the material that they are made of, they have "elastic resilience", reported Jalopnik.

Experts simply need to heat their tiny legs using a laser to bend them. The way the limbs are heated up will determine the direction of the robot. 

Therefore, the programming method is quite basic. The robots are simply "taught" the steps engineers want them to take.

While the current model is in the shape of a crab, engineers are considering other shapes like those of beetles, crickets, and inchworms.