Observing that the mobile phone and auto markets had driven a step change in the size of components, Chris Wagner and Traveler Hauptman designed a motor controller with the goal that it should be as small as possible using average manufacturing techniques. So techniques like de-lidding and wire-bonding to silicon, or using extra small PCB features that were beyond the capability of most manufacturers, but could be done by specialists we knew, were not allowed.
We designed a modular distributed motor controller. Sensing, computation, and power were separated onto different boards so that the stack could be adjusted to the application. A power section with CANBUS comms and a 2Amp H-Bridge for DC motor control was prototyped. As was a processor board using a Microchip DSPic motor control chip.
The result was a distributed motor controller with a 16mm diameter. We iterated on the processor and power boards, building several. Pieces of this project have been re-used in other projects.