THE US DEPARTMENT of Defense (DoD) is funding a three-year research study to look into micro-electromechanical systems (MEMS), which scientists believe could be used to improve the performance and efficiency of aircraft wings.
Researchers at the University of California (UCLA) in Los Angeles and the California Institute of Technology (Caltech) are using MEMS technology to build miniature actuators to control experimental wing flaps, which are hundreds of times smaller than conventional flight-control surfaces.
The miniature flaps are capable of inducing pitch and roll movements in an aircraft by controlling the symmetry of vortices at the leading edge of its wing. The flaps would each be a fraction of a millimetre in length, but an array of 100-200 flaps along each wing would be sufficient to manoeuvre the aircraft, scientists believe.
The objective of the UCLA/ Caltech study is to use MEMS technology to develop a wing, which is lighter and more responsive than one, which uses conventional flight-control-system surfaces. MEMS would be particularly useful in "flying-wing" designs, the team says.
In wind tunnel tests carried out at UCLA, a bank of MEMS flaps fitted to a scale model of a delta wing produced 70-80% of the torque generated by conventional surfaces to roll the aircraft, according to Ho Chih-Ming, professor of aerospace engineering at UCLA and who is also head of the MEMS development team.
Flaps measuring 0.2-2mm were tested, using MEMS actuators of 1-2mm in size. The actuators are manufactured from silicon-based materials, using surface micro-machining technology. High-speed aircraft will require stronger actuators with more complex geometry to withstand increased loads.
The next phase will focus on generating and controlling pitch and yaw moments in a delta wing, using MEMS. Ho says that a challenge involves locating areas on the leading edge of the delta wing where it is believed that the MEMS flaps will be most effective.
Source: Flight International