Solar-powered flapping wing. Artwork of the solid state aircraft concept developed for the NASA Institute for Advanced Concepts by researchers at the Ohio Aerospace Institute, USA. This aircraft would use thin-film solar arrays and an ionic polymer-metal composite material. The composite material would deform in an electric field, like a muscle, allowing a flapping motion. It would use solar power in the day to flap and gain height. At night it would glide until the Sun appears again. It could be used on Venus, Earth and Mars. Such aircraft could be used for exploration, or used as communications relays. The aircraft would have a 10-metre wingspan. This study was funded in 2002 (Phase I) and 2004-5 (Phase II).