While most Sumo-style robots are fairly sizable, there is a subsection of the Sumo robot movement that focuses on making small robots. Really small robots.
[Patrick] wrote in to share his latest creation, a Nano Sumo robot measuring a scant 1 in. x 1 in. The Nano Sumo is operated by an ATMega 328 micro controller housed on a custom-built PCB. The board was designed to interface directly with the 1A Dual Motor Driver from SparkFun, which provides all of the PWM signaling to the motors for speed control and braking. A small 50mAh Li-poly battery is attached to the robot, which can be charged using 4 AA batteries via a custom charging circuit. The mechanical components of the bot were handled by his friend [Gary], which you can read about here.
As you can see in the video below, the bot does its job pretty well. It does seem like the object detection gets confused every once in awhile, but that can likely be remedied with a few software tweaks.
Check out his page for additional build videos, including the PCB construction and programming processes.
If you’re interested in learning more about Sumo bots, check out this slightly larger robot we covered a short while back.