Static Electricity to Flap UAV Material Memory Wings

How can we keep aircraft and UAVs aloft longer and conserve fuel? How can we have a small MAV or UAV remain airborne for hours on end? Perhaps we should design a unit, which flies like a bird but uses the energy, which is all around us to do so. Electromagnetic Energy is everywhere. Can we design a light-weight vehicle which floats about and flaps every so often to remain airborne? Well as technology gets better with polymer muscles and built in material memory; where the substance is manufactured to keep its original shape like the toy;