TL;DR

Researchers at the Université Libre de Bruxelles achieved a stationary chemical reaction front. They balanced the flow of reactants to freeze sunray-like ripples in place. This discovery allows for the steady observation of patterns that usually vanish in motion.

Sunbeams in a Test Tube

Scientists in Belgium found a way to stop time in a flask.

In the lab at the Université Libre de Bruxelles, researcher Anne De Wit and her team have achieved what was previously thought impossible: pinning a chemical reaction front to a single coordinate. Usually, these chemical waves rush outward like ripples in a pond until they consume all available fuel. However, by balancing the injection speed of reactants with their consumption rate, the team “froze” the movement, creating a starburst pattern trapped in a glass chamber.

Precision at the Heart of the Reaction

The process relies on autocatalysis, where one molecule creates more of itself. Using a precision injection pump, the team pushes a compound into the center of a circular chamber. When it meets a second reactant, a chemical wall forms.

By matching the velocity of the incoming reactant against the speed of the “chemical burn,” this equilibrium prevents the front from shifting. The resulting “ripples”—hydrodynamic instabilities known as the Saffman-Taylor instability—do not fade. Instead, they remain as permanent, sunray-like ridges that can be measured with micron-level precision using lasers.

Recent Advancements in Reaction Stability

• Integration of AI controllers to adjust pump pressure every millisecond
• Mapping of the “Sunbeam” patterns using high-speed fluorescence microscopy
• Testing of CO2 sequestration techniques using stationary mineral precipitation fronts
• Development of stationary combustion models for hydrogen fuel research

Additional Resources

• Physical Review Letters: Stationary Chemical Fronts
• ULB Nonlinear Physical Chemistry Unit
• Nature Portfolio: Chemical Physics Updates
• Phys.org: Chemical Reaction News

People Also Ask

How does this stop the “ripples” from moving?
The pump pushes fresh chemicals into the center of the chamber.

The chemical reaction wants to spread outward. When the outward push of the fluid equals the inward speed of the reaction, the front stops. Think of a person running up an escalator that is moving down. If the speeds match, the runner stays in the same place.

Why are the patterns shaped like sunbeams?
The shapes come from hydrodynamic instability.

When a thinner fluid pushes a thicker one, the boundary fingers outward. Because the front is stationary, these fingers grow into long, permanent rays instead of swirling away. Scientists call this the Saffman-Taylor instability. In this experiment, the chemistry reinforces the shape.

Can this be used in everyday manufacturing?
It is already moving into the medical field.

Researchers use the stationary fronts to deposit thin layers of polymers for drug delivery. The constant reaction ensures the medicine is coated in a layer of uniform thickness. This prevents the pills from dissolving too fast or too slow in the stomach. And the precision of the stationary front allows for smaller, more efficient sensors in wearable tech.

The information in this article reflects the latest laboratory data from the Université Libre de Bruxelles and related research published in major physics journals as of 2026.