Friday, December 4, 2009

A More Human-Like Sense of Touch For Robots

Optical pressure sensors give robots the human touch, an article on New Scientist's website, discusses a technology that may give robots enhanced sensitivity in a sensate skin.

Existing sensors, such as those based on simple pressure switches and motor resistance, are limited in their ability to detect subtle changes in pressure and to distinguish between different textures. A key reason for this is the electrical components and wires they are made from tend to be inflexible.

Building in a lot of sensors will give a robot additional useful information about what it is touching and handling. However, placing large numbers of traditional sensors close together increases the potential for electromagnetic interference.

To get around these obstacles, Jeroen Missinne and colleagues at Ghent University in Belgium have developed a flexible "skin" containing optical sensors.

The skin consists of two layers of parallel polymer strips lying perpendicular to each other to form a grid. These are separated by a thin sheet of plastic. Light is constantly fed into the polymer strips, which act like optical fibres in that their geometry encourages internal reflection and reduces light loss.

When pressure is applied anywhere on the skin it causes the strips to be pushed closer together and allows light to escape from one set into the other. The detection of this leakage of light provides a highly sensitive feedback mechanism.

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