High pressure, high forces, long lever arms...all of that meant heavy and strong (read: expensive) parts which I was not looking forward to having to fabricate. Instead, I settled on the simpler idea of harnessing the power of compressed gas. Instead of using a high mechanical advantage lever to push a piston, compressed CO2 would be dispensed from a small and inexpensive 12g or 16g cartridge which would then generate the requisite pressure to properly extract espresso. This concept is not actually novel; both an unsuccessful kickstarter and a now-defunct handheld espresso maker (with a fanatical user base) employed this mechanism.