An undergraduate chemistry researcher has developed a nail polish formulation that will let people use their nails to tap away on touch screens.
Capacitive touchscreens use weak electrical fields across their screens that respond when an electrically conductive object, like the skin of a finger or a stylus, disrupts that field. Long nails have long been a problem for smartphone users since because fingernails don't conduct electricity. There's also a dreaded condition dubbed "zombie finger," where a person's finger simply won't work with a touchscreen, usually because it's covered with thick callouses of dead skin – think woodworkers or electric bassists.
Manasi Desai, a student at Centenary College of Louisiana, has been working to solve the problem with her research supervisor, chemistry professor Joshua Lawrence. After a good deal of trial and error, they appear to have hit on a working formulation, albeit with a few areas for improvement, They presented their research to the American Chemical Society at its annual spring meeting this week.
Other researchers have addressed the problem in the past, but the results were only available in jet black or very limited colors. The method Desai and Lawrence developed can actually go on clear - to a degree.
To find their conductive chemicals of choice, the pair experimented with 50 different additives, most of which weren't effective. What did work, they discovered, were two options: A simple organic molecule known as ethanolamine, and taurine, a compound commonly found in over-the-counter health supplements and energy drinks.
While both chemicals demonstrated electrical conductivity, they haven't yet figured how to deliver them in a method that would map to normal fashion trends, as Lawrence explained to The Register.
"We have something that works, but only with an amount of polish that is decidedly not high fashion, unless 2-4 mm blobs on the end of nails is 'in' next season," Lawrence told us. The compound is also a bit gritty and doesn't last as long as they want, Lawrence explained, with the combined materials only displaying conductivity for about a day. They're seeking a solution that'll last a week, Lawrence said.
"On the plus side, it works with just a taurine acid base pair added to commercial nail polish, so the toxicity is on par with current nail polishes and energy drinks," Lawrence said. Ethanolamine, on the other hand, is a slightly toxic skin irritant, so not the ideal choice.
Interestingly enough, the compound works not based on inherent conductivity, but because of acid-base chemistry.
As explained in the ACS writeup, ethanalomine-based formulas release protons to move charges around, causing protons to jump between molecules when contact is made with a capacitive touchscreen - just enough capacitance change to register a screen touch. Lawrence told us that the acid-base chemistry wasn't something he and Desai were seeking out - it's just what worked.
Lawrence told us that, while the pair have applied for a provisional patent, he's still not sure it'll evolve into a fully functional commercial product.
"I'm a pessimist," Lawrence said. "I'm surprised it has worked this well."
The professor told us that he and Desai have a lot of work to do before they file a complete patent application, and even then he said he's not going to predict whether they've actually struck gold.
"I've worked on an awful lot of projects that hit walls right before they cross the threshold from interesting to useful," Lawrence told us.
Either way, a successful project like this, with a ACS presentation behind it, is a fine feather for any undergraduate chemist's cap. We reached out to Desai for comment on this story, but Lawrence told us she's traveling back from the ACS conference. Desai's research has already helped her land an internship with cosmetics maker L'Oréal, Lawrence told us, as cosmetics chemistry is one of her key areas of interest. ®
Source: The register