Removal of different color tattoo inks may require multiple lasers

The body can remove tattoos after they are broken down by laser

Tattoos place blobs of ink below the surface layers of the skin in packets too large for white blood cells to clear out. By breaking the ink into smaller pieces, they can be processed by the immune system, which is responsible for removing foreign matter.

Tattoo removal breaks apart ink particles

Tattoos place ink below the skin's surface layers in packets too large for white blood cells to clear out. By breaking the ink into smaller pieces, the immune system, which is responsible for removing foreign matter, can process them.

Laser procedures have made tattoo removal much more common

An increasing number of Americans, including high-profile celebrities, get tattoos removed because laser removal has become more advanced and cost-effective. The tattoo industry is adjusting to this mainstream trend.

The immune system fights tattoos

Our skin is a fascinating organ that wants nothing more than to protect our bodies from the outside world. Tattoos penetrate that protective wall to inject ink directly into the sensitive, immunologically rich layer of skin known as the dermis.

Fiber lasers used for metal engravings can’t burn your skin

These devices use diodes and mirrors to create pulses of light that vaporize metal in billionths of a second, though at wavelengths that cannot react with organic material. Pulse width, power, and speed adjustments can produce white, black, and even colored patterns through controlled heat reactions.

'Magic ink' is redefining the tattoo

One University of Colorado professor has developed an ink that can be "turned on" with exposure to UV light, and "turned off" with sunlight. While the ink could help those who want to hide their body art from family members or coworkers, there are potential uses for medical procedures.

Tattoo inks are largely unregulated by the FDA

With hundreds of ink manufacturers, all unregulated by the FDA, it’s hard to determine the exact ingredients in tattoo inks. Some pigments may contain carcinogenic chemicals, such as heavy metals and aromatic hydrocarbons, or even bacterial contaminants. Red ink often causes allergic reactions and may even contain lead or mercury.

Tattoos, explained

Tattoos last because immune cells trap ink beneath the skin—but there's more to the story. This overview looks at how ancient cultures used tattoos for status, spirituality and punishment; how technology like the electric tattoo machine transformed the art form, and where innovations like smart tattoos could take it next.

Tattoos are made by injecting pigments into the skin

Tattoo ink is injected under the skin, which can leave the body open to infections and allergic reactions. While many tattoo artists are licensed professionals who follow sanitary guidelines, that’s not always the case.

Some materials can absorb low-energy light and emit high-energy radiation

Through anti-Stokes cooling, incoming energy is combined with vibrations in a material's crystal lattice to produce a net reduction in its temperature. Using this effect, lasers can be directed at microchip hot spots to help keep data centers cool.

Blacklights can illuminate certain biological materials, including blood, teeth, and fingernails, because they contain fluorophores—molecules that visibly glow immediately after exposure to higher-energy light.

Laser-etched electric charges guide toner during laser printing

When sending a print job, the file data generates an image that a laser maps positively charged regions onto a drum separately for each color toner. Once the negatively charged toner is applied where it was electrically attracted, heat and pressure fuse it onto the paper.

Laser skin treatments can promote the production of collagen

Skin resurfacing vaporizes the top layer of skin to reveal healthier, new skin, while collagen can give the skin structure and elasticity. Such procedures treat scars and burns, but may leave light spots on the skin.

Lasers are classified based on their gain medium and mode of emission

All lasers possess a material whose atoms must be energized by a power source, such as electricity or chemical reactions. Different media will produce different colors of light through a cascade of emissions resulting from an initial stimulated emission.

Lasers can be used to reduce the motion of atoms because particles of light—photons—can collide with particles of matter, as billiard balls do, to slow them down.

Harvard and MIT researchers are developing life-saving tattoos

Tattoos aren’t just a fashion statement. Scientists are trying to find life-saving applications for them. Harvard and MIT researchers are developing tattoo inks that react to body chemicals, alerting diabetics to blood sugar fluctuations or athletes to dehydration. Someday, patients may observe their body chemistry with tattoos that change colors.

Lasers help build the layers of circuit components in microchips

During the photolithography process, light is projected through a blueprint onto a light-sensitive chemical layer on silicon wafers, etching patterns that become transistors through a series of successive reactions. These processes require significant electricity, as only about 2% of photons reach the wafer.

Laser technology powers communication, medical and manufacturing tools

Lasers are used when scanning groceries, printing documents or undergoing cosmetic procedures to enhance efficiency, precision and accuracy. Missile defense, targeting and optical communication systems have made using laser technology habitual in the military.

Lasers could be the most cost-effective tool for clearing dangerous space debris

A NASA study found that lasers from ground- and space-based systems could utilize the momentum of light to safely push smaller debris out of their orbits. These systems would need to be accompanied by amendments to international space law, which prevents any nation from touching debris from another country, among other strategies.

Random lasers can be created from biomaterials, such as peanuts and birch leaves

Rather than creating a narrow beam of light via amplification in an optical cavity, the random laser produces a red glow by scattering photons created in the natural pores of a peanut kernel after it has been injected with a solution of light-generating carbon dots derived from birch leaves.

During LASIK surgery, a laser removes microscopic amounts of tissue from the cornea

Before surgery, a patient’s vision needs are incorporated with measurements and mapping of their eye’s surface to identify corrections to refractive errors. This ensures light entering the eye correctly focuses onto the retina to produce a clear image.

Red light therapy—a treatment harnessing a specific form of energy that penetrates the top layers of skin—is marketed for skincare and wellness, but has its roots in NASA plant growth research.

NASA began investigating the healing properties of red light therapy in the 1980s, when researchers studying how LED lights could aid in photosynthesis noticed that their hands seemed to heal faster than normal under the lights.

Starting with red, colorful objects will appear to lose their colors the deeper they are submerged because water scatters light, reducing the amount available to reflect off objects and be observed.

Microchip fabricators create light by heating tin droplets to over 220,000 Kelvin

Every second, lasers strike 50,000 droplets moving at 250 kilometers (155 miles) per hour, vaporizing the tin in supernova-like miniature explosions that produce ultraviolet light. Knowing this light will spread via diffraction as it passes through a filter during manufacturing, designers reverse-engineer the filter design based on the required final microchip pattern.

Multi-material 3D printing produces filament waste if only one nozzle is used

When swapping between colors or materials in a fused deposition modeling system, a considerable amount of filament is purged from the nozzle before introducing a new filament. Filament extruders can create new filament from purged elements, but the device combines colors and produces filaments of inconsistent diameter.

Watch the engineering challenges overcome in turning a 3D printer into a tattoo machine

The DIY project required reprogramming the printer to operate on a curved, 2D surface rather than making flat layers in 3D, editing replacement firmware to bypass temperature safety checks, and developing a rapid system to stop the tattoo in case of an emergency. The final product printed "LEG" on a volunteer's leg.

Despite the visibility of lasers in space battles within science fiction, they are impossible to see in outer space unless they are pointed directly at an observer.

There are stigmas attached to tattoos

Although tattoos are fairly common in the US, some taboos remain. A 2017 study in the Journal of Social Psychology found discrimination against tattoos is alive and well, and that even individuals with tattoos associate them with negative stereotypes.

Lasers have been used to create natural adhesives for paper

German researchers at four Fraunhofer institutes have developed a method to seal paper packaging using a carbon monoxide laser. Without the need for glue or plastic adhesives, the Papure project is expected to improve the recyclability of paper. (Some readers may experience a paywall.)

Variations in the energy of light force the use of multiple telescopes

Just as Earth's atmosphere allows the sun's visible light to pass through while blocking other harmful radiation, telescope mirrors and other optics can only reflect, absorb, or transmit certain types of light. Detectors also utilize semiconducting materials that react to specific energies of light, thereby preventing a one-telescope-fits-all solution.

High-powered red light therapy—delivered directly to nerve fibers via a fiber optic needle—has been used in recent experimental research to suppress pain.

Technological breakthroughs are spurring innovations in the industry

What if you could see your tattoos before they’re embedded in your skin? Or take a virtual visit into a local studio to work out your nerves over a first tattoo? The industry is anticipating some big technological changes, from 3D designs to sci-fi upgrades to more precise tattoo guns.

The different energy levels of each element result in unique colors when burned

When heated, electrons absorb energy and move to excited states within an atom. They promptly drop back down and release light energy corresponding to the size of the drop, which is unique to each element.

When processing light, the brain can perceive colors with no natural wavelength

While some animals are sensitive to many forms of light, humans possess receptors that are sensitive to red, green, and blue wavelengths. These receptors send signals to the brain, which are processed and mixed to produce the array of colors we observe, including magenta, pink, and "supercolors" that lack a corresponding natural wavelength in the visible spectrum.

Photolithography etches circuit components into a semiconductor wafer

A high-energy laser is fired at molten tin droplets, turning them into plasma that releases the ultraviolet light needed to burn the wafer's photoresist layer. A mask controls what parts of the wafer are etched for subsequent chemical processing.

Chromium contaminants in a ruby crystal gave the world's first laser its red color

The red light originates from a long-lasting excited electron state in the element's atomic structure. The brittle gray metal has historically been used in pigment production, the manufacturing of rust-resistant stainless steel, and the creation of durable coatings with long-lasting shine for metals, wood, and leather.

Proteins with limited light sensitivity prevent humans from seeing all types of light

Specialized photoreceptor cells in the retina called cones each possess photopigments that activate when exposed to three ranges of visible light. Other forms of electromagnetic radiation outside the activation range do not generate signals for processing in the brain, thereby limiting average human vision to approximately 10 million colors.

Scientists can tag distinct proteins with fluorescent probes that emit different colors, allowing them to visualize multiple biochemical processes simultaneously.

Brain implants can help colorblind people hear colors

Colorblind artist Neil Harbisson was born into a world of grey. In 2004, he had a chip installed connected to an external color frequency sensor. Once the sensor "reads" a color, it sends a signal to the chip and plays an associated sound both in and outside Harbisson's head.

How to cook food with lasers

Creative Machines Lab at Columbia Engineering have developed a system of software-controlled lasers to cook food with precision, retain moisture with the final-cooked product, brown food within its original packaging, and create an entirely new meal creation process for a consumer. Watch this three-minute video to see for yourself.

Light appears to slow down as it travels through different materials

As electromagnetic waves interact with particles in a transparent medium, particles vibrate and generate their own electromagnetic waves. The interference of the original and generated waves, which are slightly delayed, results in ensemble light with an effective slower speed but unchanged color.

An interactive explanation of blood transfusion

The antigens and Rh factors of blood cells (which determines your blood type) must be compatible with your immune system—which is why blood transfusions between patients must have matching types. In a mismatch, the immune system will attack and destroy donor blood cells, triggering a potentially fatal reaction.

Scientists have proposed using lasers to push space trash into Earth's atmosphere

Such projects would allow most debris to burn up and no longer pose a risk to active satellites, telescopes, and astronauts on space stations. Enacting these plans would require substantial investments from private and governmental space agencies and overcoming international laws that prevent the removal of another country's space equipment.

Certain visible light therapies, when applied at specific intensities, can be used to treat skin conditions, including acne.

If surgeons removed organs, including one of your lungs, a kidney, your spleen, appendix, tonsils, part of your liver, and even some of your reproductive organs, you could still survive.

Photodynamic therapy is one current treatment for age-related macular degeneration.

The weakest form of light that is dangerous to humans is ultraviolet

Unlike radio waves, microwave, infrared, and visible light, UV light can produce chemical changes, such as curing adhesives and resins, causing substances to fluoresce, and destroying the genetic material of microorganisms. This makes UV light useful for sterilization, forensics, and quickly drying nail polish.

Scientists create contact lenses that give you infrared vision

Scientists have created lenses that use nanoparticles to convert infrared light into visible light, allowing human eyes to observe previously invisible parts of the electromagnetic spectrum. This technology may help colorblind individuals by converting colors they cannot see into wavelengths they can.

'Skin stitching' is an ancient tattoo method that's made a comeback

In the slow method, artists use needles to puncture the skin. Then, pigmented thread is drawn through the punctures to create the tattoo, resembling embroidery in the flesh. The method is experiencing a cultural revival within Canada’s First Nations communities.