Researchers at CU Boulder have developed a way to make living algae emit light for much longer than the tiny flashes seen in nature, opening the door to electricity-free lighting and other “living material” applications. The team used simple chemical solutions to trigger sustained bioluminescence in Pyrocystis lunula, an algae embedded in 3D-printable hydrogel structures that stayed alive for weeks.
The core breakthrough is that the algae’s glow can be turned on by changing the chemical environment. The researchers tested an acidic solution with a pH of 4, similar to tomato juice, and a basic solution with a pH of 10, similar to mild soap, and found that both could activate light production. The acidic condition worked best: it produced a brighter, more concentrated glow that lasted up to 25 minutes, while the basic condition was shorter-lived and more diffuse. See image above.
To make the system practical, the team mixed the algae into a naturally derived hydrogel and used 3D printing to form shapes and structures. When those printed materials were exposed to the triggering solution, the algae inside lit up the entire structure in blue. Even after four weeks, the algae in the acid-treated printed samples retained 75% of their brightness, showing that the living material could remain functional over time.
The research is a proof of concept for future technologies rather than a finished product. Possible uses include for autonomous robots that need light in dark environments, deep-sea or space applications where batteries are impractical, and living sensors that could signal water quality problems by glowing in response to toxins. The researchers are now exploring whether the algae respond to additional chemicals, which could expand their sensing applications.
Because the algae are photosynthetic, they use sunlight and dissolved carbon to live, which means the system could store carbon while producing light instead of emitting carbon the way electric lighting does. The research is an early step toward lighting and sensing materials that are both biologically based and potentially more environmentally friendly.
The CU Boulder research is a first-of-its-kind method for sustaining algae-based luminescence, 3D-printing it into useful forms, and imagining future uses that range from robotics to environmental monitoring.
To learn more, I spoke with an expert, Arif Gasilov, a partner at Gasilov Group (gasilov.com), a sustainability and ESG consultancy. Gasilov published a piece in Seaside Sustainability on how microalgae sequester carbon at rates up to 50x faster than terrestrial plants and their applications in ecosystem restoration. He has been quoted in Forbes, US News, ConsumerAffairs, and other outlets on sustainability and energy topics.
Regarding the new research, Gasilov shared:
“I think what makes the CU Boulder development interesting from a sustainability and carbon storage point of view is really the dual-function potential. Pyrocystis lunula photosynthesizes CO2 during the day and produces light at night so a bioluminescent lighting installation is removing carbon while replacing electricity. 2.2 lbs / 1kilogram of cultivated algal biomass removes slightly more than 4lbs of CO2 (1.83 kg) from the atmosphere. If you scale that into architectural lighting applications (wayfinding/ambient signage/public spaces), you have a material that provides a service (light) while performing carbon removal at the same time. No LED or OLED can make that claim.”
“But there is a caveat from a sustainability perspective: can the lifecycle carbon math hold up at scale? The hydrogels, the chemical stimulants, the 3D printing process, and the maintenance infrastructure all carry embodied carbon. And 25 minutes of sustained glow is a long way from the 50k or so hour lifespan of a commercial LED, even though it is a great development. I think the path to real-world building integration will probably look more like hybrid installations (bioluminescent accent or wayfinding lighting supplementing conventional systems) than wholesale LED replacement, at least in the near term. That said, if building sustainability certifications like LEED or WELL begin recognizing carbon-negative biomaterials in the same way they credit green roofs or living walls, that could make adoption far faster, accelerating the timeline significantly.”
More information is available here.
All images courtesy of UC Boulder.
You must be logged in to post a comment.