I intend to build a collapsible longboard fitted with various sensors. It will use normal longboard trucks/wheels, but with a 3D printed deck. The deck will contain aluminum rails, and will be able to collapse into itself, either by telescoping, or re-aligning the sections vertically.
On the board will be various sensors, possibly a camera, and a micro-controller. These will sense the board's environment, and possibly control mobility via braking. It will also collect location and movement data for fitness tracking.