A 3D-printed clay tile, designed to work as an artificial bed for coral, gets placed on the seafloor on Feb. 2 at Hoi Ha Wan Marine Park in Hong Kong. Photo: VCG

In July, a team of architects and scientists at the University of Hong Kong (HKU) used 3D printing to create the world’s first clay structures to help restore coral reefs damaged in a typhoon in 2018. Photo: VCG

The 3D-printed clay tile was designed in layers to help the coral attach and grow on it. Photo: VCG

A HKU professor shows a hexagonal 3D-printed clay tile in November 2020. Photo: VCG

A marine scientist measures the diameter of an 3D-printed clay tile underwater on Feb. 2. Photo: VCG

A diver takes a photo of a cuttlefish protecting her eggs inside a 3D-printed clay tile. Photo: VCG

Marine scientists swim to where the 3D-printed clay tiles were placed. Photo: VCG