Yasin, who was part of the school's masters programme in Innovation Design Engineering, created Petit Pli after buying clothes for his nephew that no longer fit by the time they turned up.
He used his background as an aeronautical engineer to devise a set of permanent folds that let clothes "unpack" when pulled, so they stretch over children as they get bigger.
The collection features waterproof and windproof outwear, sized to fit children aged six months to 36 months. Kids sometimes go through six clothing sizes in this period.
The designer hopes that by creating kids' clothes that last longer, it will help reduce the huge amount of waste generated by the garment industry.
"Children outgrow their clothes in a matter of a few months, yet we clothe them in miniaturised adult clothing, as opposed to designing them from the ground up," he told Dezeen. "With 11 million children in the UK, I thought it was time we redesigned children's garments."
Yasin experimented with fabrics in his own home, including adding pleats and cooking fabrics in his oven.
As part of his previous masters in aeronautical engineering, the designer had researched deployable structures for small satellites. These require carbon fibre panels to pack away into minuscule gaps before being released and holding their structure.
His understanding of folding techniques from this research heavily influenced Petit Pli, which relies on man-made materials that are currently still patent-pending.
"The structure deforms with the movement of the child, expanding and contracting in synchrony with their motion," he added.
"If this concept was actually going to enter the market, I felt that I couldn't focus on technology that was too far away from being market ready – shape memory polymers for instance. Pleats was a simple solution."
Yasin is currently raising investment for Petit Pli, and plans to make early batches in the UK, with a focus on finding manufacturers with high ethical standards.
This year's Royal College of Art graduate exhibition ran from 24 June to 2 July at the Royal College of Art's Kensington campus in London. It included everything from wearable pods that let musicians compose tracks as vibrations, to a furniture system designed to combat waste by extending the life of objects.