It’s all thanks to scientists from Slovenia and Greece, who have produced microlasers made entirely of edible materials, such as oils, butter, agar, and gelatin.

There has been growing interest in biological and biomaterial microlasers and microcavities, as groups recognize their potential for applications such as tracking, labeling, biodetection, cell barcoding, information security, and anti-counterfeiting. But there have been only a few instances where microcavities have been made entirely from edible materials and have emitted above or below the lasing threshold. New research is exploring the use of consumable materials for both the laser cavity and the gain medium.

As it turns out, olive oil contains enough chlorophyll to be used directly as a laser in the form of droplets in water. Using sunflower oil or butter as a solvent and exciting the droplets with a pulsed laser, scientists demonstrated the formation of microcavities in two different configurations: whispering gallery modes, where light circulates inside a droplet, and Fabry-Pérot cavities, where light reflects back and forth between two surfaces. Their emission properties were also shown to be tunable by adjusting the cavity size or modifying surrounding conditions, such as the refractive index of the medium.

The microlasers developed in this study can sense sugar concentration, pH, the growth of bacteria, and exposure to high temperatures. They can also encode multiple data bits — such as manufacturer information and expiration dates — while also functioning as physical unclonable stamps for anti-counterfeiting measures. Researchers believe these edible lasers could significantly enhance traceability, security, and freshness monitoring of food and pharmaceuticals. These lasers could also find use in nonedible products in environmental monitoring and biomedical applications.

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Courtesy of iStock.com/LumenSt.

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Demonstrating how this development could be used in bar-coding techniques, a specific date was encoded into a glass jar of peach compote. The barcode remained readable for more than a year after it was produced, even when stored at room temperature without any special light protection. Researchers believe these codes could last even longer if the lasers were made from a solid material embedded in an edible medium, rather than dissolved directly into food.

In the food and pharmaceutical industries, quality and authenticity are monitored through complex methods such as mass spectrometry, DNA barcoding, isotope and elemental fingerprints, and gas chromatography. But these methods rely on time-consuming and expensive instrumentation. Barcodes, for example, may be unsuitable for bulk unpackaged goods such as fruits and vegetables, and when it comes to packaged items, the barcode doesn’t help much if it is removed or intentionally covered by a sticker with a false code.

Using edible barcodes or sensors embedded directly in a product could be a more efficient practice. These codes can be read remotely using a small hand-held device and could alleviate health concerns related to counterfeiting and quality issues in the food and pharmaceutical industries. Not to mention, no more eating those stickers left on your apples and bananas!

This research was published in Advanced Optical Materials (www.doi/10.1002/adom.202500497).

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