Inspired by many questions that make use of utility fog.
Utility fogs are not, as the name might suggest, fogs, but rather lattice solids.
Cells of the foam are pollen-like micrometer-scale machines physically connected to one another by robotic arms. When they run out of power, or are ripped off the lattice by force, the machines try to recover -- or fall to the ground.
Foglets are produced by some outside device. Once deployed, will eventually degrade to nothing as casual-use damage to the lattice accumulates.
Are they feasible? What can they do?
Here are the specs. Feel free to look here for additional material.
- Body is 10 micrometers in diameter
- Has up to twelve arms, 5 micrometers in diameter and 50 micrometers long giving a fully-extended reach of about 100 micrometers, and a fully-contracted volume of 10 micrometers per cell
- Made or shrouded in aluminum oxide. Density of alumina allows ranges between 3,000 to 4,000 kg per cubic meter
- Arms have a tensile strength of about 100,000 psia. Compressive strength is about 800,000 psia (from this source).
- Hands (connecting nodes) has a tensile strength of 1,000 psia.
- Sensors : best available with current technology
- Processing : 100 million instructions per second, or best available
- Power : best available with current technology (maybe supercapacitors).
- Computational Power Consumption : best available (I found ~45 Watts per terahash on a Bitcoin mining site) and 1 hash $\approx$ 12,700 operations
- Operating Mode : continuously on while deployed. Evaluating objects attempting to pass into the fog and adjusting shape as required.
- Failure Mode : individual micromachines stow their arms and go inert when disconnected from the lattice and unable to re-attach. Micromachine nodes also stow and go inert when power failure is imminent.
Uses of utility fog :
- As a seat belt alternative / safety restraint
- On-demand construction of roads
- On-demand furniture and non-consumable household goods
- Moving objects, people
- Solid telepresence or entertainment content
So, here's a few specific questions :
- What is the minimum (stowed) volume of 1 kilogram of this utility fog?
- What is the maximum (fully extended) volume of 1 kg of utility fog?
Would it be dangerous for a human being to be enveloped in this medium:
- Are the 50-micrometer arms a physical injury hazard?
- Is ingestion or inhalation a physical injury hazard?
- Are "soft spots" (eyes) in danger from being enveloped in a utility fog?
How long could a utility fog stay in active operation before running out of power?
How much pressure can a 1kg utility fog exert on an enclosed space? Does the maximum utility fog force scale with the density of the utility fog? (think the answer is "yes" given the slender arms).