This video shows NASA researching folding wings, in what looks like a model of an airliner. What would be the benefit to this technology?
It would allow an aircraft to have a wingspan of >80 meters yet still be able to be serviced at a standard airport gate.
There are a variety of benefits to longer wingspan, but the major drawback is that commercial passenger airports are designed around that 80 meter box.
It looks like these wings have ends that fold up to become winglets, for drag reduction at high speed, and down to increase wing area, and thus lift, at low speed for takeoff and landing.