Another idea someone already thought of

I had this idea for a while about about robotics but I recently found out that it's already been thought of. here's what it is in a nut shell, people want to create robots and humanoids and to do that you need acutuators of some sort to act as the individual mussles, currently there are solenoids, stepper motors, experimental muscle wire stuff, pneumatics and hydraulics. but they all suck in their own way. Meanwhile systems that rely on combustion reactions, like gas engines provide large kinetic potential since it relies on the expansion of gases in a combustion reaction, the idea is to create an actuator that operates on an expanding fuel, the system would be much like a system of pneumatic cylinders that use an expanding fuel kinda like the cylinders in a gas engine only with a unique fuel possibly a monofuel that reacts with a catalyst in the cylinders.

well here's the paper that proposes what I thought was my idea I haven't read the whole thing because I'm not paying for a membership