This Instructable will teach you how to create magnetic robots that traverse vertical surfaces. These robots can move on any metallic walls, including elevators, whiteboards, refrigerators or metal doors.
The robots are outfitted with several light sensors, allowing them to respond to simple user interactions. My implementation supports 3 robot 'personalities', which can be changed by covering the topmost light sensor:
Red robots move fast, going towards objects (such as human hands or other robots)
Green robots move slower, turning away from objects
Yellow robots move the slowest, and stop completely when motion or objects are detected
This instructable details my first prototype. In the future I plan to build in more complex, autonomous behaviors. I will use these robots to engage people in public spaces such as elevators or hallways. In doing so, I hope to facilitate creative interaction between people and technology in mundane, everyday settings.
Human Computer Interaction Institute
Carnegie Mellon University
for Making Things Interactive, Spring '09
*** UPDATE ***
I recently made another version of this project using continuous servo's from sparkfun and a custom-cut PCB. The new robot is much much sturdier: