Utility fog is a collection of nanobots or nanotechnological robots, envisioned by Dr. Josh Hall while he was thinking about a nanotechnological replacement for car seatbelts. The robots would be microscopic, with extending arms reaching in several different directions. Grabbers at the ends of the arms would allow the robots (or foglets) to mechanically link to one another, enabling them to act as a continuous substance with mechanical and optical properties that could be varied over a wide range. Each foglet would have substantial computing power, and would be able to communicate with its neighbors.

In the original application as a replacement for seatbelts, the swarm of robots would be widely spread-out, and the arms loose, allowing air flow between them. In the event of a collision the arms would lock into their current position, as if the air around the passengers had abruptly frozen solid. The result would be to spread any impact over the entire surface of the passenger's body.

Utility fog is sometimes thought of as a nanotechnological version of the Swiss army knife.

External links

• Dr. Hall's original writeup
• A more detailed description
• Article at KurzweilAI.net