Super-thin Finnish foil heats up – and can be bent
The metal foil is 0.05 millimeters thick and can be used in everything from underfloor heating to textiles – or to keep food deliveries at the right temperature.
In Finland, the state-owned VTT, the Technology Research Center, has developed a heating element that can be bent, stretched, and is also extremely thin.
The net consists of a metal foil having a thickness of 0.05 mm, corresponding to 50 micrometers. The material is produced by printing electronic components with a so-called roll-to-roll method, R2R, in a printing press. However, VTT does not share any more detailed technical specifications of the material.
The unique thing about the invention is that no other layers are added to the metal foil. The only limiting factor is that the material with which the heating element is joined must be transferable.
– Since we only transfer the heating structure, the specific properties of the material are not affected. So, for example, if we transfer the structure to a textile, the fabric will still behave like a textile, and be elastic and so on. And if we transfer it to fiberglass, we can create structures without affecting the mechanical properties of fiberglass, says Terho Kololuoma, the project’s lead researcher at VTT to Ny Teknik.
The size of the foil can be tailored, and the properties open up a number of application areas. Among other things, VTT is developing a new solution for food transport, where the temperature is kept above a critical 60 ° C, as harmful bacteria can quickly grow in a cooler environment.
Another possible application is as laminate on tables or other surfaces that can be quickly disinfected by raising the temperature to 130 degrees. But Terho Kololuoma believes that underfloor heating will be a large area of application.
Existing solutions impractical
Existing solutions with pipes or loops laid in the concrete are not so practical when renovating older properties – then it is easier to install a thin laminate. And the solution can provide environmental benefits.
– Because the foil is very close to the surface, it reacts quickly. When you turn on the heat, it comes almost immediately – that means you can reduce the general temperature in the building, and when you get home you can raise it. In the Nordics, we have around 21 degrees indoors, but the whole building does not need such a high temperature. If we can reduce the general temperature by, for example, five degrees, we can save 25 percent in energy when we are not in the building, he says.
The heating element is transferred to other materials from roll to roll. Photo: VTT
You can also, for example, heat a cool basement wall with a wallpaper that contains the foil. The researcher also sees the possibility of dividing the home into different zones – and in the future adding intelligence where different people can be identified in different rooms.
– We will be able to control the heat locally, you will not waste energy where it is not needed. And if the person you live with wants it a little warmer than you do, it works – while you may feel comfortable with 18 degrees, says Terho Kololuoma.
There are, of course, safety aspects that must be weighed in, and the researcher states that he does not currently have all the answers – but the aim is for the heating element to be below 50 volts.
The Technology Research Center in Finland is not developing end products, but during the first quarter of 2022, a spinoff company will be started to be responsible for the commercialization of the technology.
