Researchers in Canada have developed a new diagnostic technology that could identify melanoma before it becomes visible to the naked eye. The system, described as an “intelligent tattoo,” uses microscopic needles, nanoparticles and ultrafast imaging to detect subtle temperature changes associated with early-stage skin cancer.
The technology, known as SMEAR-ULM, was developed by scientists at Institut national de la recherche scientifique in collaboration with researchers from Université de Montréal. According to the researchers, the platform could support earlier diagnosis of melanoma while reducing the number of unnecessary biopsies associated with current screening methods.
Growing need for earlier detection
Melanoma remains one of the fastest-rising forms of cancer in several countries, including Canada. Early diagnosis is critical because survival rates decline significantly once the disease spreads beyond the skin. Current diagnostic pathways largely depend on visual inspection by dermatologists, often followed by biopsies of suspicious lesions. While effective in many cases, these approaches can miss extremely small melanomas or lead to invasive procedures for benign skin abnormalities.
Professor Jinyang Liang, senior author of the study, published in Nature Sensors, and specialist in ultrafast imaging and biophotonics, says the goal was to create a minimally invasive method capable of detecting aggressive melanomas at a much earlier stage. The researchers focused on temperature as a diagnostic signal. Cancer cells generally consume more oxygen and nutrients than healthy tissue, producing slightly higher levels of heat through increased metabolic activity. Until now, however, these thermal differences were too subtle and imprecise for reliable clinical use.
How the ‘Intelligent Tattoo’ Works
At the centre of the system is a temporary patch containing painless microneedles that deliver specialised nanoparticles just beneath the skin surface. These nanoparticles effectively create a temporary “intelligent tattoo” that functions as a network of microscopic temperature sensors. When exposed to near-infrared light, the nanoparticles emit visible light. Importantly, the duration of that light emission changes depending on the local skin temperature. The warmer the tissue, the different the optical response becomes.
Using an ultrafast optical imaging platform, the system captures these signals in a single high-speed measurement and converts them into a detailed thermal map of the skin. The technology provides submillimetre spatial resolution and can detect temperature changes smaller than one degree Celsius. According to lead author Yingming Lai, the single-shot imaging approach enables rapid and robust monitoring, even under complex biological conditions.
Detecting ‘unvisible’ melanoma
In preclinical testing, the researchers successfully identified micro-melanomas only four days after formation, far earlier than conventional imaging systems can typically detect. Traditional thermal imaging methods based on infrared technology often struggle with low spatial resolution and background noise. As a result, they usually detect only larger tumours measuring more than five millimetres, which are already visible during routine skin examinations.
The new system combines microneedle technology, rare-earth nanoparticles and AI-supported ultrafast imaging to overcome these limitations. The researchers believe this effectively transforms skin temperature into a measurable biomarker for early melanoma detection.
The study was conducted in mice, although the researchers note that the animal model closely replicates genetic changes observed in human melanoma. Professor Sylvain Meloche from the Institute for Research in Immunology and Cancer at Université de Montréal says the findings could eventually support earlier intervention in patients with aggressive skin cancers.
Broader potential
Beyond melanoma detection, the research team believes the SMEAR-ULM platform could be adapted to monitor additional physiological indicators, including pH levels and ion concentrations. That broader capability could position the technology as a future platform for minimally invasive biomedical imaging and precision diagnostics across multiple disease areas.
While clinical application remains some way off, the study highlights how advances in nanotechnology, optical imaging and biosensing are increasingly converging to create new forms of non-invasive, data-driven diagnostics for personalised healthcare.
Swedish study
A couple of weeks ago Swedish researchers showed that AI can identify melanoma risk patterns up to five years before diagnosis. The study analyzed healthcare data from more than six million Swedish adults, of whom 38,582 later developed melanoma. Using information such as age, gender, medical history, medication use and socioeconomic factors, AI models detected subtle risk patterns that traditional methods often miss. The most advanced model predicted future melanoma cases with an accuracy of around 73 percent, compared to 64 percent for models using only age and gender.
Researchers also identified smaller high-risk groups with a melanoma risk of up to 33 percent within five years. According to the team, the findings could support more targeted screening, earlier intervention and a shift toward preventive, data-driven precision healthcare.
