Integrating microcontrollers with motors, sensors, and 3D printed parts, I designed and built this gyroscope for my Physics IB Extended Essay.  The gyroscope's speed can be set precisely using PID control up to 6600 RPM.  A load cell and a stepper motor allow precise torque control around the axis perpendicular to that of the gyroscope's axis of rotation.  An angular position sensor at the base measures the speed of gyroscopic precession.  The data was great! (See pages 28 and 30 for graphs)

I programmed this voice-activated calorie tracker as part of Beta Camp, a month-long accelerated business program.  You simply describe your meal, and it returns the calorie count, voila!  My team and I decided to make the app free after Beta Camp.