New 3D-printed robotic hand could transform patients' lives

British roboticist Joel Gibbard has developed a prototype prosthetic hand which he claims could be constructed for a fraction of the cost of traditional artificial limbs, using 3D printing.

The hand, known as Dextrus, is made from the same kind of plastic as LEGO bricks, meaning that it should be hard-wearing and durable without costing as much as titanium or carbon fibre - the materials used in current prosthetics. A rubber coating gives the hands a skin-like feel.

Steel tendons hold each finger together just as in a biological hand, with miniature electric motors taking the place of the muscles. Gibbard claims that the Dextrus is capable of a greater range of movement than other artificial hands, and should enable users to grasp differently-shaped objects in a number of ways.

Each finger is operated separately, and contains a feedback sensor which knows when it has touched something, and tells the hand to stop exerting pressure. The electric motors allow for different pressures to be employed, enabling the hand to pick up delicate items as well as lift heavy household goods. Each finger is tested to withstand 18kg of load, and thanks to a spring-mounting system, will not be knocked out of position by small collisions.

Bristol-based Gibbard, who is currently seeking funding for the project, says in his video pitch that 'Leading prosthetics can cost up to $100,000. By using emerging technologies like 3D printing, we can cut that down to under $1000. That's two orders of magnitude cheaper, and means that these devices can reach a far broader audience!'

The plastic parts of the hand can be 3D printed, meaning that replacement digits will be cheap and easy to add. Early tests and calculations show that the hand, which is powered by lithium ion batteries, will last between eight and 12 hours on a single charge.