Researchers at MIT have built electronics so small they can be sprayed out like a mist.
The electronics are about the size of a human egg cell, and can act as tiny manmade indicators with the ability to sense their surroundings and store data.
On Monday, the team of MIT researchers published their findings, which involve grafting microscopic circuits on “colloidal particles.” These particles are so tiny —from 1 to 1000 nanometers in diameter— that they can suspend themselves indefinitely in a liquid or air.
To create the tiny machines, the MIT researchers used graphene and other compounds to form circuits that can chemically detect when certain particles, say some poisonous ammonia, are nearby and conductive. The circuits were then grafted on colloidal particles made out of a polymer called SU-8. For power, the machines rely on a photodiode that converts light into electrical current.
In their experiments, the researchers successfully used the tiny electronics to identify whether toxic ammonia was present in a pipeline by spraying the machines in aerosolized form. In another experiment, the electronics were able to detect the presence of soot. As a result, the researchers say the technology could be handy in factories or gas pipelines to detect potential problems.
Another use case is for medical care. The tiny machines could be sent through someone’s digestive system to scan for evidence of diseases.
However, one big limitation with the “aerosolized electronics” is they can’t communicate wirelessly. All data is stored on the tiny machines, which can be scooped out from a liquid or caught in air, and then scanned to access the results.
To make them easy to spot (at least under a microscope), the electronics are fitted with tiny reflectors. But in the future, the MIT researchers hope to add some communication capabilities to the machines, so that all data can be fetched remotely.
The researchers published their findings in Nature Nanotechnology on Monday.