A New Nail Polish Might Someday Solve Touch Screen Struggles for Users With Long Fingernails
The experimental coating could effectively transform fingernails into touch screen-compatible styluses
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/accounts/headshot/SarahKuta.png)
:focal(4128x2752:4129x2753)/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/filer_public/37/5f/375f6455-57e4-4bec-a6f5-774330d60e9e/nail-polish.jpg)
From smartphones to tablets, touch screens are everywhere these days. But this ubiquitous technology can be challenging for some people to use, such as those with long fingernails.
An experimental nail polish could help solve the problem. Researchers at Centenary College of Louisiana are developing a clear coating that might effectively transform fingernails into touch screen-compatible styluses, and they presented several prototype formulations on March 23 at the American Chemical Society’s spring meeting. While it’s not a commercially viable product, the nail polish could one day revolutionize how some individuals move through the tech-driven world.
“This is huge, because it shows that functional behavior can be embedded invisibly into everyday cosmetic materials,” says Shuyi Sun, a computer scientist at the Association of California Nurse Leaders who was not involved with the research, to Science News’ Skyler Ware.
The invention is the brainchild of Manasi Desai, an undergraduate studying chemistry and biology at the college, and her research supervisor, chemist Joshua Lawrence. After noticing that people with long nails often struggle to use their smartphones, they wondered if chemistry might offer a solution.
“Chemists are here to solve problems and to try to make your world better,” Lawrence says in a statement.
Most smartphone and tablet screens have transparent glass with an ultrathin, electrically conductive coating, which generates a small electric field. When an object that can conduct electricity, such as a fingertip, touches the surface, it disrupts the electric field. The device detects this disruption and uses its location to perform functions like scrolling, typing and zooming in.
The process, however, works only with conductive materials. Unlike the skin on human fingertips, fingernails do not allow electricity to flow. And sometimes a person’s fingertips lack the conductivity to interact with touch screens, due to dry skin, for instance, a phenomenon known as “zombie finger.”
So Desai and Lawrence set out to create a conductive polish that would give fingernails a small electric charge. Previously made polishes contained potentially hazardous metallic additives and came only in dark or shimmery shades due to their conductive ingredients.
“One of our major goals was to make it clear and colorless, so that you could apply it over any manicure or even on your bare nails,” Desai tells Science News.
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/filer_public/68/60/68602867-5e2e-4931-886e-d84fcc5570d4/s26_touchscreen_nail_polish-2.jpeg)
To make a transparent, nontoxic version, she examined 13 commercially available clear-coat nail polishes and tried mixing in more than 50 unique additives. So far, the best option seems to be a blend of taurine, which occurs naturally in the body and is often used in dietary supplements, and ethanolamine, an organic compound with a stinky, ammonia-like odor that’s commonly used in industrial processes. When the researchers dried the resulting nail polish into a hardened chunk and held it between tweezers, it effectively activated touch screens.
“We’re doing the hard work of finding things that don’t work, and eventually, if you do that long enough, you find something that does,” Lawrence says in the statement.
They suspect the nail polish works via acid-base chemistry principles, per the statement. Taurine is an acid, which wants to donate a positively charged proton, while ethanolamine is a base, which wants to receive a proton. When the polish interacts with a touch screen’s electric field, protons probably make the leap, which changes the polish’s capacitance just enough for the screen to register a touch.
Fun fact: The first nail polish
Many people credit the Chinese with inventing the first nail polish, which originated around 3000 B.C.E., reports the Guardian’s Funmi Fetto. Individuals soaked their nails in a mixture of egg whites, gelatine, beeswax and dyes from flowers, resulting in a shiny red-pink color.
Desai and Lawrence’s invention is still a work in progress, so you may not find their nail polish on store shelves for a while. Their best formula does not always work when painted onto a nail, and the crucial ingredient ethanolamine can be hazardous to human health and evaporates fast. “All our formulations lose efficacy too quickly,” Lawrence writes in an email to Live Science’s Kristina Killgrove. “They stop working after hours or days, and we want them to work for days or weeks, minimum.”
Still, the researchers believe their product shows promise, and they’ve submitted a provisional patent for it.
“Right now, we have a good proof-of-concept material but need to do a lot more work,” Lawrence tells Live Science.
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/accounts/headshot/SarahKuta.png)