The science behind the viral tinfoil frizz trick on TikTok

It is a small downside of hot, dry weather: static hair that sticks up in a Worzel Gummidge -style halo.

Now a viral TikTok video has suggested a simple solution for static frizz that does not require sprays or straighteners. Simply smoothing hair down with a piece of aluminium foil appears to magically produce a sleek silhouette.

Scientists say the trick works by discharging static that builds up on hair after it is brushed. In warm weather, the humidity in the air is often lower, meaning there is less water in the air to conduct the electric charges away from hair. Fine hair, which lifts up more easily, is particularly susceptible to the problem.

“The frizz is caused by static charge,” said Prof Richard Syms, of Imperial College London. Different hairs will both be either positively or negatively charged, meaning the individual hairs repel each other.

Aluminium is one the best metallic electrical conductors, meaning that when it touches the hair it carries excess charges away.

“Wiping one material with another can transfer charge between them through a process called the triboelectric effect,” said Syms. “In this case, the charges initially transfer to the tinfoil. The tinfoil is a conductor, and allows the charges to be conducted away.”

From the foil, the charge will transfer on to your hand and down to the floor – unless you are wearing insulating shoes, so the trick probably works better without wearing rubber-soled boots.

The basic concept of static electricity is that when two objects are rubbed together, electrical charges are transferred from one to the other leaving one object positively charged and the other negatively charged.

But while rubbing balloons on heads is a staple of the school science fair, the physics of static electricity is surprisingly complicated. It is not easy to predict, for instance, which of a pair of materials will become negatively charged (gaining extra electrons) and which will become positively charged (losing electrons).

Laurence Marks, emeritus professor of materials science and engineering at Northwestern University in the US, and author of a landmark paper on the theory of static electricity , said: “The sources I see on the web indicate that hair is often positive. However, none of them actually seem to have measured it, so it could be an urban myth.”

Using a metal hairbrush might help reduce static in the first place. And if you have no tinfoil to hand, another option is just waiting for the effects of static to naturally disperse over a short period of time. “If you want to see what can really happen with static electricity, type ‘van de Graaff generator hair’ into Google and look at the images,” said Syms.