Well, the standard BEAM Robot is made up of a solarcell, 2 transistors and a motor. Majority of them are made using 2 photo-sensors, 2 motors and 1to 4 numbers of 74XX14, 74xx240 digital gate ICs.
Wonder where you heard about BEAM? There will always be an explanation about it.


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BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. BEAM uses simple techniques and always uses components NOT meant for the specific purpose. I used audio amplifiers from a taperecorder to drive the Robots, when I was a kid, for example.
The technique used for BEAM is Nervous Networks and is patented by Mark Tilden. The BEAM Robots mimic and look like insects. They are fabricated using funny techniques like 'free form' where all the components are connected to each other without any PCBs.

BEAM circuits look deceptively simple, but it is not simple to make them work. It needs a good understanding of Electricity and Electronic components. If not, the making of a BEAM bot will teach you these things, anyways, by the time they work !