When Marvel Studios released Iron Man in 2008, it was all the rage among comic book fans, film geeks and engineers alike. The Iron Man suit is one of the coolest and most iconic gadgets in film history. A generation of mechatronics engineers were inspired after watching Tony Stark build the suit, myself included. Now we wonder whether we could build it with today’s technology. So, the question remains: can we build the Iron Man suit?

We are talking about the Mark III suit, the gold and hot-rod red one. Unfortunately, replicating the suit is impossible; the laws of physics would not allow it. However, we can make some compromises and find some workarounds to build the suit’s most defining systems.

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The Power Source

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We can all agree the most vital part of the suit is the power source. After all, it gave Mr Stark the idea for the suit. The suit is powered by an arc reactor, which is essentially a fusion reactor (1). These produce power using nuclear fusion, the same way the sun and stars burn as enormous balls of fire. We are talking about reactions between atoms which are the building blocks of everything. Atoms contain a cluster of even smaller particles inside. Collectively they form the nucleus, so you can see where nuclear fusion comes from. Now, where are we going with this? Well, when nuclear fusion occurs, heat energy is produced (2).

Nuclear fusion was chosen as the suit’s power source due to the colossal amount of energy it produces. With the palm of your hand acting as a size guide, nuclear fusion is one of the highest energy density methods available. Sounds too good to be true, right? Correct. To replicate the conditions required, a reactor would need to be heated to 150 million degrees Celsius (3) - 10 times hotter than the sun’s core! Imagine that on your chest! Unsettling, to say the least. Mr Stark’s arc reactor is self-sustaining and can power the suit for hours, or even days. But with modern technology, fusion reactors consume more energy than they produce (4). Consequently, recreating an arc reactor of the same size and energy output is currently impossible. 

Nevertheless, there are workarounds to create a partially functioning arc reactor. Massachusetts Institute of Technology (MIT) has been working on a fusion reactor called the ‘Alcator C-Mod’ for the past 20 years (5). Their goal has been to reduce their size while maintaining power output. Typical fusion reactor size ranges from three to nine metres in diameter, but MIT has managed to reduce theirs to about one. Assuming fusion reactors are net-positive energy producing and well heat-insulated, we can assemble the Alcator C-Mod into our own arc reactor. There are many more factors that are too complicated for us and thus we will ignore them. Instead of being placed on the chest, it can be a giant backpack!

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​The Flight System

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Now, why do we need so much power? Well, the flight system consumes the bulk of it, which leads to the next point. In the movie, Iron Man flies using the repulsors on his gloves and boots. They are not gas turbines like jet engines. The suit does not carry fuel – how could it? It does not have any storage compartments. The fuel must come from outside of the suit. Here is a hint: it is everywhere, yet invisible at the same time... Air! Helicopters fly by pushing air downwards with their rotors. This works according to Isaac Newton’s third law, which states that any force will have an equal and opposite reaction. By pushing air downwards, the helicopter goes upwards. Iron Man does not have a giant rotor, so how did he solve this? Get ready for another round of physics!

Repulsors use muon beams to control flight as needed. Muons are particles smaller than atoms. They exist in the Earth’s upper atmosphere (6), but can also be created at large research facilities. For now, let us assume Mr Stark has a way to produce them on his own; remember, he is a billionaire! The muon beams are ignited using plasma made by the heating of air. To produce this on-demand, the suit draws power from the arc reactor for heating and the suction of air. The repulsor beams are then created, ready for flight! 

Muons have a short lifespan - about a millionth of a second. In real life, muon storage is not a viable option; they must be generated on the spot. Muon creation occurs in particle accelerators (7). These are long tubes for accelerating and making particles collide at high speeds. You may have heard of the Large Hadron Collider in Switzerland, a particle accelerator that is 27km long. Through efforts to miniaturise them, researchers at the SLAC National Accelerator Laboratory have designed one only 30 centimetres in size (8). Ignoring some laws of physics and with a few billion dollars, we can fabricate this into our own repulsors. Keep in mind - the suit’s hands and feet are smaller than 30 centimeters. Our gloves and boots will be longer and bulkier.

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The Future

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So there we have it - a semi-reasonable arc reactor and a flight system. Fun to explore the possibilities of current technology, right? But we must also consider the ethics of building such a deadly weapon. Yes - the Iron Man suit is a weapon. In the wrong hands, this technology would not be so exciting. Centuries or even decades from now, scientific breakthroughs may allow the replication of the suit. When that happens, as humans, it will be necessary to contemplate the moral consequences of such an advancement. 

Here we have only examined two principal systems of the suit. The rest is up to you! Traverse your mind and create your own semi-realistic Iron Man suit. As we saw here, the Iron Man suit is not far off from our time. Who knows what the future holds?