Researchers from Warsaw University of Technology will protect buildings against earthquakes

What is a Shear Thickening Fluid (STF)? It is a special fluid that thickens on impact or under other type of sudden pressure - and after a while it returns to its original viscosity. Such a fluid usually consists of hard particles of ceramic oxides (such as silica) placed in a liquid organic chemical compound.

The preparation of such fluids is not easy. In order to obtain a shear thickening fluid, its ingredients must be mixed in the right proportions and in a suitable manner - especially that the highly desirable properties of shear thickening fluid are also an obstacle during its preparation - the fluid`s behaviour must be controlled during mixing.

"Fortunately, we solved this problem a long time ago" - said Małgorzata Głuszek, a member of the research group at Warsaw University of Technology says in an interview with PAP. This group has been working for many years on practical applications of shear thickening fluids under the supervision of professors Mikołaj Szafran, Gabriel Rokicki and Marcin Leonowicz. Their achievements include demonstration versions of sports protectors and caps with helmet functions, as well as a finished product - a hidden wear bulletproof vest.

One of the latest ideas of Warsaw scientists is using shear thickening fluids for protection against earthquakes. They would be used as fillings for buildings in areas threatened by seismic shocks. The idea has already gained international recognition: in September it won a gold medal at the international Taiwan Innotech Expo.

The idea behind the invention is simple: shear thickening fluids are placed in special chambers with pistons, mounted in the foundations of buildings. During an earthquake, shocks move the pistons that cause the thickening of the fluid around them - the whole device works like a damper.

"One shock absorber would be good for about two years" - explains Małgorzata Głuszek. "After this time, you have to recycle the fluid, repeat the mixing process and, if necessary, supplement ingredients" - she adds. The developers of vibro-insulators are aware that this is not a one-time sale of the product, they must provide technical assistance for the years to come. "There is no way that someone would buy these materials and after a few years they become useless" - the researcher says.

It is a difficult task because it requires a shift from laboratory work to professional industrial production. But this vision does not frighten Warsaw researchers. "We do not want to sell our invention abroad" - emphasizes Małgorzata Głuszek and adds that the group has already found Polish investors, including one strategic investor. "Contracts are already signed and we are developing. We already have the funds to increase production, it`s only a matter of time" - she adds.

The work on vibro-insulators is a new experience for scientists from Warsaw University of Technology. So far, their research has focused primarily on protecting the human body. But Małgorzata Głuszek reveals that contrary to appearances, it is much more difficult to obtain, for example, bulletproof vest fluid than fluid for dampers that protect buildings against shocks.

"Fluids for vests are much more complex, they have more ingredients, they are also exclusive products, they are not produced on a large scale. Industrial fluids are much easier to obtain, which makes sense from an economic point of view: you need a lot more fluid for a building than for a vest, so it must be cheaper and easier to manufacture" - she explains.

PAP - Science in Poland

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