In current affairs news: Teen boffin with lots of potential crafts electric honeycombs out of oil
He'd teach you about ions and mysterious structures but he'd have to charge
A teenager studying electrically charged particles has captured the formation of an ill-understood electric honeycomb structure called the Rose window.
The Rose window – named after stained-glass designs in Gothic churches – is interesting to physicists, because how electricity moves through fluids is important for printing, heating, and biomedicine.
When an electrode connected to a needle point ionises air molecules onto a thin film of oil in the presence of an electric field, weird things happen. As the field is cranked up, the ions begin to pile up and sink, creating a dimple in the surface of the oil. This morphs into clusters of hexagonal shaped cells like honeycomb.
The Rose window instability has been observed for decades, but hasn’t been explored much. Muhammad Shaheer Niazi, a 17-year-old student at the Lahore College of Arts and Sciences, decided to investigate the phenomenon further.
It’s caused by a buildup of charged ions that create an electrical pressure on top of the oil film. As they try to make their way back to the grounded glass electrode placed underneath the dish of oil to complete the circuit. But since oil is a poor conductor, they get stuck and accumulate and sink until their weight causes a wrinkle in oil’s surface, and they can flow down to the plate.
There is now an instability in the thin film of oil between the force of gravity trying to keep its surface horizontal, and the electric field pulling it down. It then tries to even itself out by forming the hexagonal patterns.
Niazi confirmed that the instability was indeed due to the system trying to get to equilibrium by using thermal imaging in a paper published on Wednesday in journal Royal Society of Open Science. He noticed that the needle and the corona discharge of particles were at higher temperatures from the friction caused by the movement of ions through the fluid.
When he blocked the charged ions reaching the surface of the oil, causing an “ion shadow”, the pattern did not form.
It’s interesting since the hexagonal structure is often found in nature from honeycombs to rafts of bubbles, and makes sense since the pattern minimises the surface tension of the oil. ®