Robust vacuum balloon metamaterial

Advanced atomically precise manufacturing allows to build a new class of aeronautic balloons that use vacuum instead of lifting gas. The necessary support structures that counter the external pressure can be made fine and filigree enough such that the whole structure is still lighter than air.

Proof of principle

This capability is already demonstrated by a few special aerogels today but unlike todays aerogels balloon metamaterial is an advanced atomically precise metamaterial and shows much more resilience against physical attack (crunching/ripping).

Mechanical stability

Chrunching: When it is crunched it reversible folds down to a state with almost no void gaps rasing its compressive strength to almost to the level of solid matterial. Obviously it will stop floating for the time it stays crunched. The material can (and probably should) get designed in such a way that when it gets crunched it stores at least enough energy such that the subsequent (undamaged) unfolding - which has to work against atmospheric pressure - can be easily performed.

Ripping: When a force acts on the balloon-metamaterial that pulls it apart the internal structure can reversibly align into the axis of the polling force again like in the compressive case to the point where it becomes almost as dense as solid material and reaches almost the tensile strength of solid material. In practice one probably wants to put in a safety limit way below the strength of carbon nanotubes (See:"[Self limitation for safety]" and "[Sharp edges and splinters]"). Pulling in all directions simultaneously (which natural occurring forces can't do) should rip the metamaterial apart easily. A malicious attack with utility fog may be possible (further analysis needed).

Base material quartz

Since earth's atmosphere contains oxygen any material that burns easily is problematic. While diamond does not burn in its bulk form the a highly filigree metamaterial structure would burn very vigorously. The solution is to use a material that is already in its oxidized state. Best options are Silicon dioxide (quartz) aluminum dioxide (sapphire) or titanium dioxide (Rutile/Anatas/Brookite). Biominerals like calcite and hydroxylapatite also do not burn since they are based on oxides of carbon and phosphorus respectively. necessary internal nanomachine bearings may be made out of silicon carbide (moissanite) it burns but builds up a glass layer that prevents further burning.

Applications

• Various forms of "airmeshes" e.g. for transportation wind power and weather control
• massive redirection of sunlight
• low mass air transport

Price

Since the density is lower than 1kg/m^3 (three orders of magnitude lower than dense material - factor 1000) huge volumes can be filled cheaply. Since for fire safety reasons atmospheric carbon dioxide can only be used in small quantities lithospheric mining is required making it a bit more expensive than dense carbon rich diamondoid products.

Relation to the conventional lifting gas method

Avoiding the use of the very scarce element helium may lower price from todays perspective albeit we may import that element from space in the future if we figure out how to get it out of the potential well of Uranus and Neptune. Its unclear how safe hydrogen microcompartmentalized in glass metamaterial could be - maybe comparable to methane hydride - (TODO: closer investigatin required).

External links

• (TODO: add link to video showing aerogel flake floating and rising in air)