A METAL object has been made to evolve in a similar way to a simple living creature. Siavash Haroun Mahdavi and Peter Bentley at University College London have created an antenna that can optimise its shape to achieve the best reception of a particular radio signal.
The umbrella-shaped antenna is made from a sheet of aluminium foil on a springy metal frame, which is held in shape by 16 wires made of a nickel-titanium alloy called nitinol (see Diagram). Each wire can be made to contract by up to 8 per cent by passing a current through it, so…
