these 3D-printed terracotta tiles are being used to rejuvenate hong kong's coral reefs

researches at the university of hong kong (HKU) and of the swire institute of marine science (SWIMS) have 3D-printed clay and terracotta structures that aim to rescue corals found in the waters of hong kong. called the reformative coral habitats, the project aims to install massive 3D-printed terracotta tiles measuring 65 cm in diameter and weighing around 20 kg that will help corals anchor and grow.

in 2018, the mangkhut typhoon destroyed 80% of the corals near moon island at the north end of the san kung peninsula in hong kong. since the recovery of the corals could take decades, the team of researchers at hong kong university created the reformative coral habitats where they developed 3D-printed terracotta tiles that have coral pockets, allowing them to grow both vertically and horizontally. for the project, researchers chose clay as the ideal material because it doesn’t change underwater conditions.

‘the tiles aren’t conventional tiles. hong kong’s subtropical climate entails much underwater sedimentation,’ explains assistant lecturer lidia ratoi. ‘that’s why our tiles have a lot of perforations so that sediment doesn’t deposit on the surface and suffocate the corals. the pockets are big enough to allow the corals to grow both horizontally, to become sturdy, and vertically, so that they can compete with other underwater species such as algae which may suffocate them. corals grow only during the warm season. it’s vital that they are forced to grow in a vertical direction.’

the tiles were tested earlier this spring in a simulated environment where they have been growing. since the successful trial, the team has printed 128 more clay tiles which were deployed last month. the researchers will monitor the coral regrowth in the next years and they project that at least a 40-square-meter area of coral habitat will be restored.

project info:

name: reformative coral habitats

developed by: researchers vriko yu, david baker, and phil thompson from the swire institute of marine science (SWIMS) of the university of hong kong (HKU) are collaborating with architects christian j. lange, lidia ratoi, dominic co lim, and jason hu from the HKU faculty of architecture’s robotic fabrication laboratory