Muscling in on the millennium

The quest to design the first android has resulted in the revisiting of a 100 year old technology

If, next year, you decide to brave the crowds and head for the Dome, there’s every chance that, amongst the giants of British innovation, London based robotics specialist Shadow will be demonstrating exactly why it has been generating so much excitement recently.

Established in 1987 as an independent research group, the purpose of the Shadow project is the design of a domestic android. Back in 1985, MD Richard Greenhill outlined a dream which is still alive today. Greenhill looked forward to a utopian future where, rather than displacing humans, robots create a new era of leisure and opportunity: “ can people talk about not having anything to do if the robots `take over’ when the one thing this world needs above all else is labour power?”

In the course of research for this project, a number of fascinating technologies for actuation, sensing and control have emerged.

The Air Muscle, recently granted official millennium product status, is one such spin-off. Consisting of a rubber tube wrapped in a plastic weave which shortens in a scissors action when pulled out, it mimics the action of a biological muscle.

When actuated with a supply of compressed air, the air muscle contracts by up to 40% of its original length. The contraction is accompanied by a force inversely proportional to the degree of contraction. The first few percent of travel provides a large force: a small muscle filled by low-pressure air cannot be stopped by hand.

The simplest use is to move a lever; one muscle will pull the lever in one direction, and a spring can return it. Two muscles will allow the lever to be pulled in either direction, and, because the muscle contracts over a known distance, it can be used to provide a safe movement, only moving the lever through the angle it’s set up to.

The muscle has already appeared on a number of Shadow’s own prototype robotic applications: including a mine clearing robot, and a bi-pedal robot – Shadow Walker – (pictured right).

However, Shadow is not alone. Pneumatics specialist Festo recently launched its own version of the same technology, the fluidic muscle, at the Hanover Fair. Demonstrating one possible application, Festo invited visitors to board the Pentapod, an interactive chair operated by pneumatic muscles and controlled by joysticks fitted to the chair’s arms.

Shadow Tel: 0171 700 2487

Festo Tel: 01252 775000