Patternable, Lightweight Radar Absorbing Materials

Not Available Interest in micro unmanned aerial vehicles (abbreviated as MAVs and defined as less than 6 inches in their longest dimension) is increasing due to their ability to avoid detection and give combat forces a flexible and immediate intelligence source. While vehicle concepts abound, they all face a common problem; very low-speed flight requires proportionately more power than higher speed flight. This creates a need for a small, light weight, high energy density power supply. One way to achieve the needed energy density is to build the power supply function into another part of the vehicle through the use of multifunctional structures. This can be done by fabricating wings with monopolar fuel cells as their external surfaces, serving as both wing surface and power supply. This produces only a minimal increase in drag, and forward motion supplies air, with only 50 cm2 of cell area required to supply 5 watts of power. The internal portion of the wing serves as the fuel tank, with the fuel cell stack as one surface. Further weight reductions can be achieved by using the metal current collectors within the fuel cells as antennas.