This May 1, 2025 essay for The Conversation (also here on the Carleton University website) by Keroles Riad (postdoctoral nanotechnology fellow, Carleton University, Ottawa, Canada) brings to mind the myth of Prometheus (the Titan who defied the ancient Greek gods of Olympus and gave fire to humanity), Note: Links have been removed,

Fire is arguably humanity’s earliest discovery. It was pivotal in advancing society — underpinning many of humanity’s most transformative inventions, from cooking and forging weapons to generating energy and enabling car combustion engines.

Today, fire continues to be the gateway to some of the most cutting-edge nanotechnologies currently being developed for use in cancer treatments and as breath sensors for early detection of diabetes and other metabolic diseases.

Nanotechnologies can be found in almost every aspect of our daily lives. For instance, I have previously written about the nanotechnology used in the mRNA vaccines that helped us through the pandemic, and have facilitated conversations discussing how nanotechnology affects our wine, gut and climate.

For example, gas sensors incorporating nanoparticles made via fire can be used to verify that there’s no methanol in alcoholic beverages. Methanol is a highly poisonous alcohol contaminant, and has caused numerous poisonings worldwide.

Fire is how most widely used nanoparticles — and by extension, nanotechnologies — are made. For example, a third of a car tire’s weight is comprised of carbon black nanoparticles, which are made using fire. These nanoparticles help to reinforce the tire. The white paint we use on our walls and the coatings on some pills contain fire-made titania nanoparticles. Similarly, fumed silica — which is used in the optical fibres needed for internet and communication systems — are also forged in fire.

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Riad’s May 1, 2025 essay goes on to provide a definition for nanotechnology and describe some of his own work, Note: Links have been removed,

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So how do nanoparticles, which are 80 to 100 thousand times smaller than the thickness of a human hair, form inside a fire?

I specialize in making nanoparticles in fire — specifically using a technology called flame spray pyrolysis.

In my research, I burn flammable chemicals that contain the target metal elements to form my nanoparticles. Everything gets oxidized during combustion: carbon becomes CO2, hydrogen becomes water vapor and metal elements become metal oxides.

During the milliseconds that these metal oxide particulates spend inside the fire, they collide and grow into nano- or micro-particles. I collect these particles on a filter on top of the fire. Important properties such as the size and crystal structure of the nanoparticles that are produced depend on how much time these particles spend inside the fire.

The more time the particles have to collide inside the forging fire, the larger they grow. We can also make complicated particles consisting of multiple elements by burning a mixture of different chemicals. This process is both versatile and scalable — allowing millions of tonnes of nanoparticles to be produced each year.

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If you have time, Riad’s May 1, 2025 essay is a good introduction to nanotechnology both its possibilities and some of its limitations.