Written by Alan Barker, writer, academic proofreader, coach and training consultant. Find out more about his work here. at: http://bit.ly/16sGqnJ

Dr Imogen Riddell began her lecture with robots. We might think of them as human-sized metal monsters – or perhaps as tiny spaceships cruising the blood vessels (Fantastic Voyage, anyone?). What if we could make a molecular robot, instructed not by code but by chemical signals?

That, in essence, is what Imogen and her colleagues are aiming to create. She is a Kathleen Ollerenshaw Fellow at the School of Chemistry at Manchester University, and she specialises in supramolecules.

It turns out that the term ‘supramolecule’ – meaning literally ‘beyond the molecule’ – is not that easy to define. Molecules are groups of atoms held together by a covalent bond: they share electrons. Supramolecules are molecules created by other kinds of bonds. The two strands of molecules that constitute the elegant double helix of DNA, for example, are held together by a hydrogen bond. The architecture of DNA is like a railway track; Imogen is interested in different kinds of structures, and the functional properties that such structures might confer. It’s a matter of finding the bonds that work, and that is as much a matter of trial and error – at times, of instinct – as hard research.

The field is only 35 years old, and already it has attracted two Nobel prizes (in 1987 and 2016). As yet, however, the potential applications are only just becoming apparent. Perhaps the most readily available at the moment is Febreze: unlike other air fresheners, the product uses cyclodextrins: tyre-shaped supramolecules that capture odour molecules and make them undetectable. (The image at the head of this post is of cyclodextrins.) As Imogen says, “they provide a cloak of invisibility”: the smelly molecules have not been destroyed, merely wrapped in the supramolecule. We were treated to an in-depth analysis of the odours generated by smelly trainers: all three can be captured by the differently shaped supramolecules in Febreze.

Cyclodextrins are examples, then, of container molecules. Their interior space is the right shape to contain another molecule without destroying its function. Just as you could carry ice cream around on a hot day in a cold box to stop it melting, these supramolecules could transport other molecules into environments which might otherwise damage or destroy them.

Some of the most exciting potential applications are in medicine. “If you can package a drug molecule in a container molecule, for example,” Imogen told us, “you could take it orally so that it would survive the acidic environment of the stomach – and then you could deliver that drug directly into the bloodstream.” Good news for anyone like me, temperamentally averse to hypodermics.

Other applications are industrial. While she was doing her PhD, Imogen and her group published a paper about encapsulating P₄ – white phosphorus, a notorious chemical weapon. The paper suggested a method of using supramolecules to clean up a spill.

Another important application involves capturing SF₆: sulphur hexafluoride, which is essential as a gaseous insulating material for high-voltage circuit breakers and switchgear, but is also one of the most potent greenhouse gases. “We have container molecules,” Imogen explained, “that can capture, recycle and reuse it.” The trick is to find a way of disintegrating the container molecule in order to release the SF₆ when you need it.

It’s all about finding the right size and shape of molecule to pick up whatever needs to be picked up. Imagine doing a 3D jigsaw at the atomic level. Despite the cutting edge sophistication of the research, the structures that work are all based on Platonic solids: classical geometry developing crystalline structures to engineer new architectures.

What next? “I’m interested in making bigger structures,” Imogen told us, “and containers with multiple cavities.” (Think molecular egg boxes...) Perhaps the most intriguingly, she is working on self-assembling supramolecules: chemical machines that might construct themselves, just where they’re needed.

This field is clearly wide open. As so often at the British Science Festival, we felt that we were given a privileged preview of a potentially thrilling future.

Read an interview with Imogen Riddell here.

Find out more about the British Science Festival https://www.britishsciencefestival.org/ and follow us on Twitter @BritishSciFest #BSF17