AFTER buttoning up a lab coat, snapping on surgical gloves and spraying them with alcohol, I am deemed sanitary enough to view a robot's control system up close. Without such precautions, any fungal spores on my skin could infect it. "We've had that happen. They just stop working and die off," says Mark Hammond, the system's creator.

This is no ordinary robot control system - a plain old microchip connected to a circuit board. Instead, the controller nestles inside a small pot containing a pink broth of nutrients and antibiotics. Inside that pot, some 300,000 rat neurons have made - and continue to make - connections with each other.

As they do so, the disembodied neurons are communicating, sending electrical signals to one another just as they do in a living creature. We know this because the network of neurons is connected at the base of the pot to 80 electrodes, and the voltages sparked by the neurons are displayed on a computer screen.

Rise of the rat-brained robots