Imagine a packet filled with a mixture of nuts—cashews, hazelnuts, almonds, and peanuts—jumbled together and enclosed in the stifling darkness of a mirror-lined packet. More importantly, there are also a handful of Brazil nuts, larger than the other nuts, scattered throughout the mixture. When the packet is shaken, the Brazil nuts are likely to rise to the top while the smaller nuts sink lower into the mixture. This phenomenon is known as the “Brazil nut effect,” which occurs in mixed granular systems where larger particles tend to rise to the top when the system is shaken or vibrated.

Miguel Albino, a master’s student in Mining and Geological Engineering at Instituto Superior Técnico, analysed the “Brazil nut effect,” but not with nuts. Instead, he focused on granular mixtures of lunar soil in the context of space resource exploration, using 3D simulation models. His study was conducted in collaboration with Imperial College London, which provided experimental data featuring different types of samples.

Through this project, the student demonstrated that the “Brazil nut effect” is stronger in lunar gravity, with segregation observed in all tests (unlike some under Earth gravity conditions). The effect of vibration frequency was also studied, revealing that very low or high values impair particle separation. The best segregation occurs when the amplitude and frequency of the vibration are in balance, at a ratio close to 1:1.

“Since I started my master’s programme, I wanted to do something a little different. I have a strong interest in the field of space”, shares Miguel Albino. Técnico served as a great platform for him to explore this interest, “especially because of the open-mindedness of the professors” who guided him. “The project was a valuable learning experience and, above all, it was fun”, he shares.

Between 19 and 21 May, Miguel Albino attended the Space Resources Week 2025 in Luxembourg, where he won the award for Best Poster in the Fundamental Science category.

His goal for a potential PhD is to expand his research in this area. “It warms my heart to have achieved something and to have something to present. The best part was experimenting, failing, and learning”, he says with a smile.