Creating QR Codes from Living Bacteria

Using living bacteria to store information is not a new idea. For years, researchers have experimented with bacterial patterns, fluorescent microbes and bio-based codes. But despite the intrigue, these approaches have remained laboratory curiosities, largely unsuited to real-world security or authentication.

A newly published study ¹ from researchers at the Key Laboratory of Functional Polymer Materials, Nankai University, China, solves the practical problems that previously held bacterial coding back, by using light to decide which bacteria live and which die.

Why earlier bacterial codes fell short

Earlier attempts at ‘bacterial cryptography’ struggled with several fundamental obstacles.

First, most systems relied on genetically modified bacteria to produce visible signals. That limited them to specialised strains, complicated production, and raised regulatory and safety concerns.

Second, arranging bacteria into precise, machine-readable patterns proved difficult. Techniques such as micro-printing or inkjet deposition were low-resolution, slow, and fragile, producing patterns that blurred as bacteria spread.