At the Massachusetts Institute of Technology, technology has been developed to bring fantastic ideas about microscopic robotic assistants to life. It is a spray that contains nanobots, passive automatic sensors tuned to detect specific types of threats. It is enough to spray an aerosol in a dangerous place and read the signal to draw conclusions.
The nanobot consists of a substrate and an active part. The first is a colloid, an insoluble particle, or a stable molecule. It is too small and light, therefore, due to collisions with each other and the movement of the atmosphere, a suspension of such particles does not have time to fall to the ground under the influence of gravity, but soars in the air for a long time. If you spray a spray at the beginning of a pipe and blow a stream of air through a fan, it will fly through it collecting information.
The active part of the nanobot is represented by a thin, two-dimensional, like graphene, nanosized fragment of matter. It is sensitive to a specific compound, for example, ammonia; after a chemical reaction with it, it sharply improves its electrical conductivity. Attached to this material is a simple photodiode that generates an electrical current when light enters. When a nanobot stumbles upon a scattering of ammonia, its properties change, a stream of electrons jumps through the system, which is fixed by a memory device. Disposable sensor.
Without a colloidal base, nanobots will not fly anywhere, but in conjunction with it, they can be passed through pipes and through vessels in the human body. It remains only to catch at the exit, at least with a piece of gauze, and then count the number of triggered nanobot sensors. And make a conclusion about the presence of specific substances in the object under study, without the need to penetrate into it. How much this will simplify and secure the diagnosis of everything and everything, one can only dream of!