Researchers at the University of Colorado Boulder have developed a way to “sustain” algae’s bioluminescence, potentially replacing toxic chemicals and electricity with living light. 

The team has figured out how to keep these organisms glowing far longer than nature ever intended. The bioluminescence of Pyrocystis lunula algae was sustained using chemical solutions rather than physical agitation. 

In this new work, these organisms were embedded in 3D-printed hydrogels to create living structures that remain bright for nearly half an hour and remain viable for weeks. If scaled, it could offer a carbon-negative alternative to lighting in the future.

“This project was a moonshot idea,” said Wil Srubar, professor in the Department of Civil, Environmental, and Architectural Engineering. “I was curious if we could create a world in which we don’t use electricity but rather use biology to produce light. This discovery really paves the way for engineering other living light materials and devices.”

Algae experiment

Bioluminescence occurs when organisms, such as the marine alga Pyrocystis lunula, produce light through internal chemical reactions. 

However, in the wild, the algae are the ocean’s introverts, and only glow when they are bothered, like jolted by a crashing wave or the hull of a passing boat. These flashes are brilliant but fleeting, lasting only a fraction of a second.

Srubar and his team wanted to know if they could overcome the physical agitation and use chemistry to “sustain” the glow

The researchers experimented with the algae‘s environment, and discovered that shifting the pH levels — specifically using an acidic solution similar to tomato juice — can trigger a sustained glow lasting up to 25 minutes. 

This shift from momentary flashes to prolonged illumination suggests that chemistry can act as a “light switch,” transforming these photosynthetic organisms into long-lasting, carbon-absorbing light sources for future technology.

To transform the bioluminescent algae into a functional technology, researchers suspended the cells within a biocompatible hydrogel and used 3D printing to create intricate, glowing structures. After this, a sustained blue glow was activated across the entire material by applying acidic or basic solutions to the printed shapes. 

The algae survived the printing process. Remarkably, the algae remained healthy and active in this gel environment for several weeks. And those treated with an acidic stimulant maintained 75 percent of their initial brightness even after a month of use.

“It was a very exciting moment when we found the right chemical stimulant that allowed the light to stay on for a long time,” said Giulia Brachi, the first author and research associate in the Department of Civil, Environmental, and Architectural Engineering.  “This is the first time we have figured out how to sustain luminescence.”

Future applications

As these algae survive on sunlight, seawater, and CO2, they represent a lighting source that actually cleans the air.

The researchers envision a world where autonomous underwater robots use glowing skins to navigate the deep ocean without heavy batteries. These living materials could also serve as canaries in the coal mine for water safety, glowing brighter or dimming in the presence of specific toxins.

For now, the team is looking for more chemical triggers and wants to see just how much control they can exert over their tiny, glowing collaborators. If they succeed, the future of light will be both bright and alive.

The study was published in the journal Science Advances on May 6.