Robot slugkiller ready to roll

Not the farmer's friend: The black slug (Image: Dr Bill Symondson)

By BBC News Online's technology correspondent Mark Ward in Prague

Farmers could soon be relying on robots to stop their crops being eaten up by hungry slugs.

Researchers are working on a robot that can patrol fields looking for slugs and scooping up any it finds.

The creators of the robot hope it will eventually be able to recharge its batteries using power generated from the decaying bodies of the slugs it has caught.

Slugbot: One mean machine ready to go

It has already performed well in field trials and now more cash is being sought to finish its development.

Slugs are a big problem for British farmers, who spend £20 million annually trying to stop them munching young crops down to their roots.

Dr Ian Kelly, the University of the West of England researcher developing the slugbot, said up to 200 slugs could be found in every square metre of winter wheat - enough to fuel the robot.

He said he was keen to make the robot as self-sufficient as possible to make it more lifelike.

"We are trying to aim for autonomy in the way that animals are, in that it has to supply and manage its own energy so it can survive for a long time unaided," he said.

No licence needed

He said slugs were picked as a power source because they moved slowly and could do little to evade capture.

"To chase an animal that was moving quite fast would take a lot of energy," he said, adding that slugs are one of the few animals that can be hunted without a Home Office licence.

Grabber and slimewipers at the ready

The robot has been equipped with a 1.8-metre arm on a turntable that scans the surrounding soil as the machine moves.

A 164 x 124 pixel camera on the arm looks for slugs, using red LEDs to illuminate the soil. "Under red light, the mucus layer on a slug appears quite bright," Dr Kelly said.

The camera must work in low light, because slugs come out to eat only for two hours after sunset and two hours before sunrise.

The end of the arm has blades, which scoop up any slug the robot spots. These are dumped in a hopper on the robot's body to be transported back to the refuelling station.

Although the outbreak of foot-and-mouth disease in the UK meant that field trials had to be postponed, the slugbot has performed well in early indoor trials and correctly identified 70% of the slugs in an artificial field.

Now the university is actively seeking extra funds to keep the development going, and to pay for work on the fermenter that will produce power by burning biogas generated by the decaying bodies of the slugs.

Slugbot images courtesy and copyright of the University of the West of England