The Formica project was our favorite presentation at 25C3. The goal is to build open source swarm robots as cheaply as possible. The team ended up building 25 robots in an assembly line fashion. With enough lead time, the price could get as low as £15 each. Each bot has two direct drive cellphone vibration motors with tiny neoprene wheels. They’re controlled by an MSP430 microcontroller. The only really specialized chip is a charge controller so the bots can charge without any intervention. They have copper skis on the front that touch the ground plane plus antennas to contact Vcc. On top of the bot are three IR detectors for both navigation and for transferring firmware updates between bots. A reflective sensor is on the underside for detecting “food”. It looks like a great design and any easy way for anyone to start researching swarm robotics.