A stretchable metal skin for micro air vehicles (MAV) will be tested in March at the US Virginia Polytechnic Institute and State University. The test MAV is a radio-controlled model aircraft with a 1.53m (5ft) wingspan. The length of the wing and its camber and sweep can be adjusted in flight.
A skin that is able to stretch smoothly as the wing moves should solve airflow problems suffered by morphing aircraft. These occur where shape transition causes the surface of traditional metal skin to become uneven, causing aerodynamic turbulence and flight instability.
The stretchable material that is expected to solve this problem is called Metal Rubber by its manufacturer, Virginia-based Nanosonic, which is also funding the research. "The tests will also help us understand flight control needs during the transitional morphing periods. We want to do windtunnel tests but we have no target dates for that," says Dr Rick Claus, president of Nanosonic.
Metal Rubber has electrical conductivity properties and can act as a strain gauge. This can be used as a sensor to monitor the morphing movement. The testing will be complete in March so a report can be made to an undisclosed organisation supporting Nanosonic's work. Nanosonic is itself investing over $1 million of funding.
ROB COPPINGER / LONDON
Source: Flight International
