Underwater exploration may become easier in the future thanks to a new prototype crab-like robot invented by a Bath University postgraduate student.

’Nature knows what works best and can be a source of inspiration for engineering design,’ said Charles Gage, the Biomimetics & Technical Creativity MSc student who developed the crab-bot. ’Crabs are perfect models for the kind of robot we wanted because they are ‘tried and tested’ amphibious vehicles. We studied the way crabs walk, their posture, gait and stride length. Then we applied this information on a model robot.’

The robot was built to copy the features of crabs with four pairs of legs divided in two halves. Hence, the design is very stable, allows changes in direction, and prevents mechanical interference between the legs. The robot can also vary its walking speed by changing stride length, just as crabs do in nature, whilst maintaining the same motor speed.

This unique approach makes the robot very energy-efficient, according to Gage.

’We tested the crab robot on Minehead Beach in Somerset in early September 2007. The Lego-based robot performed exceptionally well and tackled the beach easily, scrambling over pebbles and small stones,’ he added.

There are a few toy robot son the market that look a lot like real crabs, but the Bath robot is very different because it is built like a crab and walks like one. Gage now hopes to develop the prototype further to create a robot with full amphibious capabilities and improved stability under different conditions.