Tesla Turbine

 The Tesla turbine was patented by none other than Nikola Tesla in 1913. They use the boundary layer effect rather than fluid impinging on the blades. It's a high RPM low torque motor. So, applications can be somewhat limited in the traditional sense of what we think of as uses for motors. Though, Tesla himself envisioned using them in cars and other highly practical applications. 

Check out these Instructables to see some projects others have built and post one of your own!