Edible Micro-Laser Paves Way for Ingestible Food and Drug Sensors

For the first time, scientists have developed a micro-laser made entirely from edible materials—a breakthrough that could lead to ingestible sensors capable of monitoring the properties of food and pharmaceuticals. The research was conducted by teams from Slovenia and Greece, and now have been published in Advanced Optical Materials.

Conventional lasers typically rely on non-edible materials like aluminum, gallium, and arsenic. In contrast, this new laser uses common cooking oils such as olive and sunflower oil as the optical medium. During the experiment, researchers exposed droplets of olive oil to violet light. The droplet's surface confined and reflected photons, amplifying the light. Chlorophyll molecules in the oil were excited by the light and emitted photons, initiating a cascading effect that turned the droplet into a functioning micro-laser.

The characteristics of the laser—such as intensity and wavelength—are influenced by the droplet's size and density, allowing it to serve as a sensitive probe. Researchers demonstrated its potential by analyzing laser changes to infer properties like sugar content, acidity, heat exposure, and microbial growth in food. In another demonstration, seven sunflower oil droplets of specific sizes were embedded in preserved peach slices to encode the date "April 26, 2017"—symbolizing the International Day of Awareness of Food Loss and Waste.

This innovation not only broadens the scope of laser technology but also lays the groundwork for future ingestible sensors, with promising applications in food safety and medical diagnostics.