“Intelligent Tattoo” Method Detects Early Melanoma Signals

Current evaluation relies on visual inspection followed by biopsy, which can miss nascent lesions and lead to unnecessary procedures. Clinicians need minimally invasive tools that identify malignant change before a lesion is visible. To help address this challenge, scientists have developed an “intelligent tattoo” that maps microscopic heat signals associated with emerging tumors.

SMEAR-ULM is a microneedle-encoded thermo-dermoscopy system created by researchers at Institut national de la recherche scientifique (INRS), Université du Québec, working with Université de Montréal. It is designed to detect skin cancers at their earliest stages by reading tiny temperature variations at the skin surface. The platform turns temperature into a precise diagnostic signal intended for rapid, noninvasive assessment of suspicious lesions.

At the core is a patch of painless microneedles that deposits specialized nanoparticles just beneath the epidermis. When illuminated with near-infrared light, the particles emit visible light whose emission lifetime depends on local temperature. An ultrafast imaging module captures the signal in a single shot to generate a detailed thermal map with submillimeter spatial resolution and sub-degree sensitivity.

In preclinical tests in mice, the approach detected micro-melanomas as early as four days after they formed. By comparison, conventional infrared thermal imaging is limited by noise and spatial resolution and typically detects tumors only when they exceed about 5 millimeters and are already visible. Existing microneedle sensors also require repeated measurements, whereas this system delivers real-time, single-shot thermal mapping in vivo.

The study was published online in Nature Sensors on May 20, 2026. The work was carried out in close collaboration between groups at INRS and Université de Montréal. The researchers report that the method could reduce unnecessary biopsies, improve early diagnostic accuracy, and support clinical decision-making, and they suggest the platform could be adapted to map other physiological parameters such as pH or ion concentrations.

"Our goal is to provide a minimally invasive tool to detect very small, but still aggressive melanomas. Because of their small size, (the melanomas) are usually excluded from clinical visual inspection, which leaves the threat unwatched. We want to detect them, so that intervention can be made as soon as possible," said Jinyang Liang, the study's senior author, who specializes in ultrafast imaging and biophotonics at Institut national de la recherche scientifique (INRS).

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