Fluidhand gets a grip

Engineers are testing a new type of prosthetic hand that is claimed to give users the sensation of a natural grip by mimicking the functions of a spider's legs.

The Fluidhand is the creation of researchers at the Orthopaedic University Hospital in Heidelberg, where the first prototype version has been trialled by an 18-year-old patient.

Its developers claim that unlike conventional prosthetics, the Fluidhand can close fully around objects, even if they have an irregular surface.

It also needs less gripping power to hold an object and gives feedback on grip strength to the stump of the user's arm.

The hand is based on flexible drives located within the movable finger joints which operate on the same principle as spiders' legs.

When the joints are flexed, elastic chambers are pumped up by miniature hydraulic systems, allowing fingers and thumb to be moved independently.

Fluidhand's developers claim the test patient had reacted enthusiastically to the device, and plan to fit it to a second patient soon. They are also looking for manufacturing partners to take the hand towards serial production.

A second prosthetic hand developed by UK company Touch Bionics is also undergoing trials at the German hospital.