B.E.A.M stands for Biology, Electronics, Aesthetics, and Mechanics. This is a style of robotics that primarily uses simple circuits instead of microprocessors in order to produce simple designs.
They were invented by Mark W. Tilden who created a circuit (or a Nv net of Nv neurons) which simulates biological neuron behaviours.
http://en.wikipedia.org/wiki/BEAM_robotics
Types of BEAM Bots:
1. Audiotropes react to sound sources.
2. Phototropes (“light-seekers”) react to light sources.
3. Radiotropes react to radio frequency sources.
4. Thermotropes react to heat sources.
Since I’m interested in using the sun, I have been working with Phototrope Beam Bots.
Types of Phototropes:
Power-Smart Head (Solar Trackers)
Photopoppers (Solar Bugs search for light, but can also sense obstacles).
Pummer (Stores energy during the day and releases at night).



http://www.smfr.org/robots/