Fighting coastal erosion with electricity


By Dr. Tim Sandle
June 16, 2025


Escorca coast, Serra de Tramuntana (Balearic Islands). Image by Vicenç Salvador Torres Guerola, CC BY-SA 3.0,

According to a 2020 study by the European commission’s Joint Research Centre, nearly 26% of the Earth’s beaches will be washed away by the end of this century. The reason for this is climate change: from intensifying rainstorms to rising sea levels.

Consequently, coastal erosion is an increasing threat. Moreover, current solutions, such as sea walls, are expensive and do not last. New technology, however, signals a viable alternative.

This is a bioinspired process makes marine sand more durable and hence resistant to erosion. The new process uses electricity to form a natural cement between grains of sand, transforming it into solid, immoveable rock.

In the study, from Northwestern University, researchers took inspiration from clams, mussels and other shell-dwelling sea life, which use dissolved minerals in seawater to build their shells.

Similarly, the researchers leveraged the same naturally occurring, dissolved minerals to form a natural cement between sea-soaked grains of sand. But, instead of using metabolic energy like molluscs do, the researchers used electrical energy to spur the chemical reaction.

Seawater naturally contains a myriad of ions and dissolved minerals. When a mild electrical current (2 to 3 volts) is applied to the water, it triggers chemical reactions. This converts some of these constituents into solid calcium carbonate — the same mineral molluscs use to build their shells. With a slightly higher voltage (4 volts), these constituents can be predominantly converted into magnesium hydroxide and hydromagnesite, a ubiquitous mineral found in various stones.

When these minerals coalesce in the presence of sand, they act like a glue, binding the sand particles together. In the laboratory, the process also worked with all types of sands — from common silica and calcareous sands to iron sands, which are often found near volcanoes. While the minerals form instantaneously after the current is applied, longer electric stimulations garner more substantial results.

From laboratory experiments it was found how a mild electrical current instantaneously changed the structure of marine sand, transforming it into a rock-like, immoveable solid. The researchers are hopeful this strategy could offer a lasting, inexpensive and sustainable solution for strengthening global coastlines.

Subsequent studies approach also can heal cracked structures made of reinforced concrete. Much of the existing shoreside infrastructure is made of reinforced concrete, which disintegrates due to complex effects caused by sea-level rise, erosion and extreme weather. And if these structures crack, the new approach bypasses the need to fully rebuild the infrastructure. Instead, one pulse of electricity can heal potentially destructive cracks.

According to lead researcher Alessandro Rotta Loria the need for this type of work was pressing: “Over 40% of the world’s population lives in coastal areas. Because of climate change and sea-level rise, erosion is an enormous threat to these communities. Through the disintegration of infrastructure and loss of land, erosion causes billions of dollars in damage per year worldwide. Current approaches to mitigate erosion involve building protection structures or injecting external binders into the subsurface.”

He adds, setting out the objectives of the study: “My aim was to develop an approach capable of changing the status quo in coastal protection — one that didn’t require the construction of protection structures and could cement marine substrates without using actual cement. By applying a mild electric stimulation to marine soils, we systematically and mechanistically proved that it is possible to cement them by turning naturally dissolved minerals in seawater into solid mineral binders — a natural cement.”

The research appears in the journal Communications Earth and the Environment. The research is titled “Electrodeposition of calcareous cement from seawater in marine silica sands”.