Size does matter! Nanotubes may now power implants, straight from your bloodstream

Carbon nanotubes are the rock star of new materials. Their walls are super thin but have massive potential, from forming the basis of bloodstream-powered gadgets to seawater desalination technologies to cheaper batteries.

In 10 seconds? Miniscule implanted carbon tubes, 50,000-times thinner than human hair, could be the key to battery-free wearables. These carbon nanotubes are also fine enough to sieve out salt from seawater, and thus help to provide freshwater to millions of people. (Find the science here)

Sieve out salt? Because their inner surfaces are very smooth, carbon nanotubes with a small enough diameter can allow single water molecules to flow through easily, but block out salt ions, which are surrounded by a bulky shell of water molecules when dissolved. Weaved into membranes, the tubes can remove salts from seawater more cheaply than current methods.

I hear that this is not the whole the story? Indeed, carbon nanotubes are amazingly versatile. Researchers are now testing the idea of implanted nanotube fibres acting like tiny power generators in our bloodstream, which could then power implants or sensors.

Wait, did you say ‘generate electricity’? Yep, researchers have discovered that when fluids are flowed past a yarn made of carbon nanotubes, a voltage can be detected. These yarns are flexible and stretchable, making it conceivable for them to be placed in the bloodstream or woven into fabrics. (Learn more here)

Any more applications? Electronics is another area of opportunity: carbon nanotube transistors could replace larger, silicon transistors and speed up computers. They can also be used in precise chemical and biological sensorsand to improve the efficiency of batteries, solar cells and fuel cells.

Can nanotubes have a multi-layered wall?

Carbon nanotubes are essentially cylindrical molecules composed solely of carbon atoms. Through methods like arc vaporisation to laser vaporisation, it is now possible to create a one-atom-thick single-walled nanotubes, or multi-walled ones. (Read more here)

Multiple layers allow scientists to alter the properties of the nanotube, for example how it conducts electricity or heat, by tweaking the shape formed by the layers form.

These layers are also modified chemically and physically to optimise their performance in practical applications like lithium batteries. (Find out more)

This research was curated by Shivaram Arunachalam,
Sparrho Hero and PhD student at Ecole de Téchnologie Supérieure, Montreal specialising in Nanotechnology