CinnaBot

Cinnabot is a polar-coordinate drawing robot designed to deposit cinnamon onto the surface of a cake in precise, programmatically controlled patterns. Unlike conventional cartesian gantry systems, it operates on R and Theta axes — radius and rotation — making it naturally suited to round surfaces.

The machine consists of three integrated systems: a rotating acrylic platform riding on roller bearings and driven by a gear train, a custom-designed end effector that releases cinnamon only when a vibration motor activates, and a microcontroller managing the stepper motors and limit-switch homing sequence. The result is a machine capable of drawing clean, repeatable circles on a cake (or latte).

Click around the 3D Gaussian Splat to get a sense of it!

The team was immediately on board with this completely unhinged idea because no one knew how to use food as a medium — the concept came from my partner, who is a pastry chef — I wanted to build something that spoke to her world and could draw with cinnamon on her cakes. She also promised to bake us a demo cake if we pulled it off.

Choosing polar coordinates was both a practical and philosophical decision: they are the native geometry of circular surfaces, and committing to them meant designing every system — mechanical, electrical, and computational — from scratch, without the scaffolding of existing lab equipment. That constraint turned out to be generative. It forced our team to prototype more aggressively, make stranger decisions, and ultimately produce something that felt genuinely original rather than a variation on familiar forms.