The armor and Stark's own transhuman body are powered by the high-yield arc reactor mounted in his chest.

He and several other agents accompany her to the building housing Stark's arc reactor, where they find that Stane's armor is already active.

The synthesis in the arc reactor is however unspecific.

In the movies, he makes an "arc reactor" which is put into his chest to stop the shrapnel.

In both the comics and the movies, he uses the arc reactor (or "repulsor technology") as a form of sustainable energy to help the world.

Stark builds an arc reactor that produces clean power.

He then spends his time downstairs building a new armored suit and a new arc reactor more powerful than the last one.

However, his scientists cannot make an arc reactor to power it, so he goes to Stark's house to get his instead.

Without the arc reactor, Stark cannot survive for long so he tries to get back to his workshop to find the original arc reactor.

He breaks the glass box and puts the old arc reactor in his chest.