Written by Alan Barker, Freelance Writer, British Science Festival 

Nanomaterials are essential for nanodevices, unbelievably small devices with the potential to transform ICT, healthcare, security, and energy usage. But studying something one billionth of a metre in size is tricky. Dr Jessica Boland can do it. She’s been chosen to deliver the Isambard Kingdom Brunel Award Lecture at this year’s British Science Festival. Alan Barker met her to find out more.

Jessica will deliver her lecture at the British Science Festival

Tell me what you do, in one sentence.

I use terahertz spectroscopy to study the properties of nanomaterials.

Right. So – one thing at a time – what are nanomaterials?

Nanomaterials are materials whose length, diameter or width is between one and 1000 nanometres in size (but most are below 100nm!). You may have heard of graphene? That’s a nanomaterial: it’s a layer of carbon only 1 atom (~0.3nm) thick.

‘Nano’ meaning ‘a billionth’ ?

Yes. A billionth of a metre. Interesting fact: going from one metre to a nanometre is the equivalent of going from the diameter of the sun to my height!

And why are nanomaterials so important?

Can you remember when mobile phones were the size of your head?

Sadly, yes.

And now they’re smaller, faster and smarter. This is an example of Moore’s law, which says that the number of components on an integrated circuit doubles roughly every two years. But the problem is that, as we’re shrinking the technology and placing more components on a circuit, we’re increasing the heat they produce and the amount of power they use. We’re also beginning to reach the physical limits of the materials we’re using – especially silicon. If we want to improve the performance and energy efficiency of our devices, we need new materials. Nanomaterials are one of the most promising candidates.

Devices will get smarter, faster, and more energy efficient, thanks to nanomaterials

How do you study these materials?

That’s where the terahertz spectroscopy comes in. Terahertz radiation is part of the electromagnetic spectrum, between infrared and microwaves, and has many applications. For example, it’s currently being developed for use in full body scanners at airports and to image cancer cells and tumours. I want to use this radiation to look at nanomaterials. If you shine terahertz radiation at a nanomaterial, you can look at what’s reflected back and work out how conductive the material is. Similar to how infrared cameras are sensitive to heat, my terahertz camera is sensitive to electrical conductivity. The more conductive your material is, the faster your device will be.

Cool. So, what types of nanomaterials are you looking at right now?

I’m currently investigating topological insulators. They are awesome.

And a topological insulator is?

It’s a material that’s insulating in the bulk but perfectly conducting at the surface. It’s one material – usually a compound of bismuth, such as bismuth selenide and telluride – but the bulk and the surface of the material behave in different ways.

That’s definitely strange.

It’s not what you’d expect! The coolest thing is that surface conductivity isn’t altered by any defects or non-magnetic impurities. If you put these in the way of the electrons, they just keep going. So these materials act a bit like skating on an ice-rink: the electrons will travel in only one direction, close to the speed of light, with less heat and less resistance. If you can harness this property in your devices, then your devices will be smaller and 100 times faster than they are now!

Why do we want smaller things?

Good question. It’s not just about getting smaller. We also want to make devices smarter and faster, as well as reducing energy consumption. Your phone’s battery life is still pretty poor. When you go down to the nanoscale, you start to get quantum effects, which can give you step changes in device performance: for example, speed, data storage, energy efficiency.

So my phone might not get smaller, but the circuitry inside it will.

Yes. But you’ll also get increased functionality, speed and energy efficiency. Nanomaterials can also lead to new technologies. For example, one of the things I’m interested in is creating nanodevices for a new kind of wireless communication, which will be 1000 times faster than now.

So how long before we can use these materials in new applications?

Oh, that’s at least twenty years away…

Damn.

Oh yes. My research is right at the start of the journey. I’m looking at these amazing new materials, working out how they work, and thinking about how we could use them. Going from the lab to a commercial application takes a long time. Persuading industrial companies to replace something like silicon, which works so well, is never easy, so I have a challenge ahead!

Jessica Boland delivers Smaller, Better, Smarter at the British Science Festival on Thursday 12 September at 11:00. Read more about this event and book tickets here.