It sounds like an engineering fantasy or a scene out of a Harry Potter movie, but it is real that Advanced Research Projects Agency (DARPA), a branch of the U.S. Department of Defense, is developing unmanned, single-use, unpowered air vehicles that do their job and then just disappear.
Building on recent innovations in the Vanishing Programmable Resources (VAPR) program, DARPA has launched ICARUS (Inbound, Controlled, Air-Releasable, Unrecoverable Systems), which is tasked with developing vanishing air vehicles that can be dropped from an aircraft to make precise deliveries to isolated locations and then evaporate into thin air.
VAPR researchers have already developed ephemeral materials, including a small polymer panel that sublimates directly from a solid phase to a gas phase and a glass material embedded with electronics that shatters into tiny particles after use.
In battlefields, many sophisticated technologies are often used and are left behind, which can fall into the wrong hands, making them very risky. Moreover, these discarded electronics can also harm the environment. Self-destructing electronics will rule out all these problems.
ICARUS will have other applications as well, like delivering food, water, perishable vaccines, insulin, and blood to people struck by natural disasters or epidemics, as well as for supporting military units in the field. Usually, the organizations that dispense such materials have to go back to collect the vehicles they used to drop the supplies, or they leave these vehicles to decompose.