Algae materials produce light with no power source

“An exciting feature of these materials is their inherent simplicity—they need no electronics, no external power source,” said study senior author Shengqiang Cai, a professor of mechanical and aerospace engineering at the UC San Diego Jacobs School of Engineering. “We demonstrate how we can harness the power of nature to directly convert mechanical stimuli into light emission.”

Alginate, a polymer made from seaweed, was added to the dinoflagellates as the main components of the bioluminescent materials. These substances were combined to generate a solution, which was then processed by a 3D printer to produce an assortment of shapes.

During tests, the substances lit up when the scientists applied pressure and made patterns on their surface. The materials were so sensitive that even the weight of a foam ball moving across their surface caused them to glow.

The light became more intense as more stress was applied to it. In order to mathematically forecast the intensity of the glow based on the intensity of the mechanical stress applied, the researchers were able to create a model to quantify this behavior.

Very low maintenance

The materials were also found to be very low maintenance. The dinoflagellates within the materials require regular cycles of light and darkness in order to continue functioning. When mechanical tension is applied during the dark phase, they employ the food and energy they produced during the light phase to emit light.

“This current work demonstrates a simple method to combine living organisms with non-living components to fabricate novel materials that are self-sustaining and are sensitive to fundamental mechanical stimuli found in nature,” said study first author Chenghai Li, a mechanical and aerospace engineering Ph.D. candidate in Cai’s lab.

The researchers further toyed with the materials to make them more resistant under various conditions. By incorporating a second polymer, poly(ethylene glycol) diacrylate, into the initial mixture, the researchers strengthened the materials even more so that they can withstand heavy mechanical loads. Additionally, the materials were shielded from acidic and basic solutions by being coated with Ecoflex, a stretchy rubber-like polymer. The materials continue to be enhanced and optimized by the researchers in order to reach a quality sufficient enough to see them applied in a variety of industries from medicine to robotics.