Products designed using topology optimisation are often organic looking. Round flowing shapes, with voids and with added air. Typically these geometries are difficult to manufacture, except using 3D printing or additive manufacturing. For this reason, topology optimisation and additive manufacturing go hand-in-hand.
Airplanes are obviously benefitting from weight reduction lightweight technology. The lighter the plane, the less fuel is required to get the plane of the ground and the less energy it costs to keep it in the air.