Roll-up screens 'moving closer'

One of the forms the metal can take is a tube More details

Roll-up laptop screens may be a step closer, according to scientists.

A Cambridge team have developed metal structures that can morph from flat screens into tubes and other shapes.

They say in the future the structures could form the basis for electronic displays that could be rolled-up and placed in a bag or pocket.

The scientists believe the material could also be used for re-usable packaging, roll-up keyboards and self-erecting temporary shelters.

The metal sheets, made from copper alloys, work without the need for moving parts such as hinges, latches or locks.

They "snap" from one shape into another, from a flat sheet to a coil, bent or twisted structure.

Dr Keith Seffen, the lead researcher from the Department of Engineering at Cambridge University, said they got the idea from children's toy "flick" or "snap" bracelets which transform from a straight strip into a coil around the wrist.

The principle behind the shape-shifters is manipulating the stress within the structure.

MORPHING METAL One of the morphing processes involves a dimpled structure: 1 Invertible dimples are created on surface 2 Depressing a narrow band causes metal to crease 3 When all are inverted, sheet coils up Source: ReconStruct

Dr Seffen said: "If you think of bending a ruler, when you bend it you are changing its shape and also the stress within the structure.

"The shape and stress are interconnected - the more shape changes, the greater the stress become, until eventually the object fails.

"What we have worked out is ways that you can make the shape and the stress interact with each other in a positive way."

When the Cambridge team's material is bent, like the ruler, the stress within the material increases.

But rather than going on to break, the stress level reaches a midway point and then changes to force the structure into a different shape.

Some of the structures are dimpled, and can move from a flat surface to a crease to a twisted shape.

Electronic newspapers

Dr Seffen said the material could have several different applications.

"We are producing the supporting material for flexible electronics.

"Flexible electronics is a burgeoning area, people are looking into making very thin flexible displays that could be used for electronic newspapers, or other portable electronic media like a roll-up laptop or compact mobile phone."

He added because his structures are produced from one sheet of metal, they are quick and cheap to produce, and light and easy to carry around.

Another application, said Dr Seffen, could be for temporary shelters that could be put up in emergency situations. They are transportable plus they have structural integrity, he added.