iFixit

There is a dab of glue at the tip of the tail. The articulated tail is capable of a surprising variety of movement.

How to skin a dinosaur...

The eight capacitance sensors that allow Pleo to feel are located throughout his body: two on top of his torso, one under his chin, one on top of his head, and one on the outside of each leg.

The torso is in two sections, connected by a large gear and a rotating backplate (which is the black piece on top of the front section).

According to Howstuffworks, there are two ARM7 32-bit processors which control the more complicated actions of Pleo. One processes the sensors around the head, while the other controls I/O, image processing and is "where Pleo's personality and behavior exist."

Here we see the SD card slot.

The board uses one of the four 48-pin Toshiba TMP86FH47AUG 8-bit microcontrollers.

Oh, the humanity! What have we done?

The rear torso houses the ingenious tail mechanism and rear leg drives.

To walk, Pleo has two motors driving each leg. One motor is in the torso, and the other is in the leg beneath the silver foil. Pleo uses eight motors and 36 gears just to walk around!

Pleo's tail is what gives him the most personality. It's hard to understand without seeing him move. When you pick Pleo up by the surprisingly-durable tail, he detects the resistance and direction change and immediately starts squirming and squealing. When you put him back down, he quivers in shock and fear.

The tail is composed of 19 vertebra, 4 wires, 2 motors, 8 gears, 2 force feedback sensors, and a tremendous amount of ingenuity.

Pleo's eyelids open and shut and his eyes move up and down. His mouth also opens, and when he detects something (like food) in his mouth, he clamps down and acts like a dog playing tug-o-war.

There is a speaker in his mouth and microphones on either side of the head.

We only have one Pleo, so we don't know what the IR transmitter is capable of.

The head contains a 32-bit NXP RISC LPC2103F microcontroller.