Tattoos could be turned on and off with light

Researcher Carson Bruns' fish scale tattoo, which he can turn on and off with light
Researcher Carson Bruns has a tattoo he can turn on and off with light. He can also use light to doodle on himself
Matter & Light, Bruns et al. 2026

Tattoos could be radically reimagined following the development of inks that can be turned on and off by exposing them to light. This could be used medically – or to hide the butterfly on your ankle from a judgemental relative.

“You can simply turn the tattoo off whenever you don’t want to see it and it disappears from view,” says Carson Bruns at the University of Colorado. “If you never want to see it again, just never turn it on again.”


Read more

Ancient Siberian ice mummy is covered in ‘really special’ tattoos

Bruns has had a tattoo of fish scales using this method for the past two years, and says he has experienced no known side effects. “I get a lot of compliments on the fish scale tattoo,” he says. “After over two years in my skin, I haven’t seen any obvious fading yet.”

Instead of traditional inks, which people have used for thousands of years to decorate their bodies, Bruns and his colleagues employ photochromic dyes, which change from a transparent state to a coloured one when exposed to certain wavelengths of light. They call the new technology, which has been tested on silicon, “PhotoTat”.

There is little mechanical difference between a traditional tattoo and the new inks, says Bruns. Both are pigment particles implanted in the dermis with a needle, he says. They also both stay there permanently and are applied with the same machines and methods.

The difference is the pigment, says Bruns. With PhotoTat, “ultraviolet light writes the colour in, bright visible light erases it, and the cycle can be repeated”, he says. “The tattoo is permanent, but its appearance is not.”

This could be useful in medical applications, such as for the tattoos used by doctors to guide radiation beams, which leave many patients permanently marked, says Bruns.

The light-sensitive tattoos can currently be made from 16 colours, which are clearly distinguishable from each other. From these colours, there are at least 300 different shades. White is unavailable because it reflects light, rather than absorbing it, so can’t be switched on and off like other colours. The researchers have also been unable to develop a true cyan.

Another issue is that the blue ink gradually develops a permanent, purplish colour as the dye slowly photo-degrades over many on/off cycles. Someone with one of these tattoos would also need to apply sunscreen to prevent the colour activating when they are exposed to sunlight.

In terms of safety, Bruns says the polymer that encapsulates the dyes is non-toxic and has a long history of use in permanent biomedical implants. “The colour-changing [dye] toxicity is unknown, but the toxicity of most tattoo pigments is equally unknown,” he says.

Graphene tattoo
Temporary graphene tattoos could continuously monitor blood pressure

A temporary graphene tattoo that monitors blood pressure has been awarded the highest possible accuracy grading for such a monitoring device

Still, extensive safety studies need to be carried out before the tattoos will be available to the public.

Signe Bedsted Clemmensen at the University of Southern Denmark says tattoo ink in the body is a foreign substance, which has been linked to cancer, regardless of whether it is visible or invisible. “Therefore, many of the same health considerations and concerns that apply to traditional tattoo ink are also likely to apply to invisible tattoo ink,” she says.

Earlier this year, it emerged that red tattoo ink caused one man to lose all his hair and stop sweating. Tattooing has also recently been linked to localised damage to the immune system.

Journal Reference:

Matter & Light
DOI: 10.1016/j.matlit.2026.100119

from Health – latest in science and technology | New Scientist https://ift.tt/W0JFRyQ
via IFTTT

Nearly 1 in 10 young adults could have fatty, narrow arteries

Atherosclerosis, the build-up of fatty plaque in arteries, usually affects people older than 50, but a “meaningful” proportion of younger adults also have the condition

from Health – latest in science and technology | New Scientist https://ift.tt/opskOUq
via IFTTT

The big unanswered question about Russia’s ‘plague’ death

Russia says it is winding down precautionary measures taken after a lab worker at a plague research institute died. But what made officials think these were needed at all?

from Health – latest in science and technology | New Scientist https://ift.tt/IpTbWlU
via IFTTT

Can we harness the brain’s deep-cleaning system to prevent Alzheimer’s?

The glymphatic system is the brain’s recently discovered network for flushing out toxins. Now, we’re uncovering surprising ways to boost it to protect brain health

from Health – latest in science and technology | New Scientist https://ift.tt/In617FZ
via IFTTT

Nearly 200 people isolated after lab worker in Russia dies of plague

Plague is studied in labs, where workers usually wear protective clothing
Associated Press/Alamy

A lab accident in the Irkutsk region of Siberia led to the death of a 28-year-old woman from pneumonic plague last week, according to reports from independent news outlets. Nearly 200 people who might have come into contact with her are said to have been put under observation and several hospitals in the area have been quarantined.

There is no reason to think this is the start of a large outbreak. Plague cases are relatively common worldwide but they do not spread widely because the infection is now easily treated and prevented.


Read more

How a surge in ancient plagues 5000 years ago shaped humanity

“Plague is not a historical disease,” Zania Stamataki at the University of Birmingham in the UK said in a statement. “Human cases occur every year, including outbreaks of the pneumonic form.”

The term “plague” usually refers to ill health caused by a bacterium called Yersinia pestis, although there is no official confirmation the woman’s death was due to this pathogen. Y. pestis circulates in non-human animals in many parts of the world and infects more than 1000 people every year.

The most common form of plague is bubonic plague, which is caused by flea bites and characterised by swollen lymph glands, or buboes. The bacterium can also infect blood, called septicaemic plague, or the lungs, known as pneumonic plague.

The woman in Irkutsk is said to have died of pneumonic plague two days after being hospitalised. This is the deadliest form of the condition and can spread via the air when infected people cough, for instance. However, measures such as wearing masks and avoiding close contact prevent its spread.

“This can be controlled and stopped with appropriate surveillance and control measures,” Simon Clarke at the University of Reading in the UK said in a statement. Cases are also usually treatable with antibiotics.

The circumstances of the lab accident remain unclear. It is being reported that it was caused by a broken test tube, but if proper procedures for handling dangerous microbes were being followed, this should not have led to an infection. Workers should have been wearing protective equipment, for instance.

There has also been speculation that the woman’s death was caused by a modified form of the plague created for biowarfare, but there is no evidence this is the case. Pneumonic plague is nearly always fatal if not treated promptly, so there’s no reason to think this strain is especially dangerous. What’s more, Y. pestis frequently infects animals and people, so there are legitimate reasons for studying it in labs.

The former Soviet Union did have a large bioweapons programme, which included modifying Y. pestis to make it resistant to antibiotics. Antibiotic-resistant strains have also evolved naturally, and were first detected in Madagascar in the 1990s.

Oldest known plague outbreak killed hunter-gatherer children

DNA evidence shows that plague bacteria devastated a community in Siberia more than 5000 years ago, challenging the idea that there were no major disease outbreaks before the advent of farming and large settlements

There is a long history of lab accidents leading to infections, deaths and even outbreaks. For instance, in 2007, an outbreak of foot and mouth disease in the UK was traced to labs. In 1979, at least 68 people died of anthrax in Sverdlovsk, Russia, after what the US claimed was the accidental release of anthrax spore from a military facility. There is, however, no evidence the covid-19 pandemic was a result of a lab accident.

While lab-acquired infections with Y. pestis are rare, they are not impossible, Stamataki said. “This incident warrants a full account of what happened. That account matters beyond Russia.”

Russia has repeatedly claimed that Ukraine is developing bioweapons with the help of the US, but there is no evidence for this. In 2024, it was reported that new buildings were being built at a former bioweapons site in Russia called Sergiev Posad-6.

from Health – latest in science and technology | New Scientist https://ift.tt/Dya3SiU
via IFTTT

Nobel prize for medicine goes to trio who developed optogenetics

Karl Deisseroth, Peter Hegemann and Georg Nagel being announced as the winners of the 2026 Nobel prize in physiology or medicine by Nobel committee secretary general Thomas Perlmann
Karl Deisseroth, Peter Hegemann and Georg Nagel are announced as the winners of the 2026 Nobel prize in physiology or medicine by Nobel committee secretary general Thomas Perlmann
Jonathan Nackstrand/AFP via Getty Images

The 2026 Nobel prize in physiology or medicine has been awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for the development of techniques for controlling genes with light, known as optogenetics. 

“It’s a really new era in neuroscience thanks to this methodology,” said Thomas Perlmann, secretary general of the Nobel committee. 

In the 1990s, Peter Hegemann, then at the Max Planck Institute for Biochemistry in Germany, wondered how a single-celled alga, Chlamydomonas, can swim towards light. 

In the 2000s, he and Georg Nagel, then at the Max Planck Institute for Biophysics in Frankfurt, Germany, discovered that the key to this is a light-sensitive protein that acts as a switch, opening a channel that lets ions flow through the protein when exposed to light. The protein was called channel-rhodopsin. 

Karl Deisseroth, at Stanford University, then genetically engineered rats to produce channel-rhodopsin in their nerve cells, meaning specific nerves could be activated by shining light on them. This work, published in 2005, enabled researchers to study the function of specific groups of neurons and is now widely used worldwide.  

More light-sensitive proteins have since been discovered, which respond to different colours, enabling even more precise control of engineered nerve cells.  Therapies based on optogenetics are also being developed. For instance, it is being explored as a way to restore some sight to people who are blind. 

The downside of optogenetics is that light cannot penetrate far into the body. So several groups around the world are trying to develop equivalent methods based on ultrasound or magnetism.

from Health – latest in science and technology | New Scientist https://ift.tt/1OyEzVr
via IFTTT

Should we keep children away from sugar for their first 1000 days?

The list of age-related conditions we can avoid by limiting sugar is shockingly long. But does that mean we should stop our children eating any sugar at all? Columnist Alice Klein takes a look at the evidence for cutting out sugar  from conception to age 2

from Health – latest in science and technology | New Scientist https://ift.tt/oIZmje1
via IFTTT

First week of life seems crucial for future allergy and eczema risk

The mainstream view is that there are no particularly critical phases in the development of the immune system, but a study of hundreds of infants suggests otherwise

from Health – latest in science and technology | New Scientist https://ift.tt/EJubvWH
via IFTTT

Design a site like this with WordPress.com
Get started