This Lollipop Could Help Blind Women Independently Detect Pregnancy

Design student Sneha Rao is developing Tact, an edible pregnancy test that allows people with vision impairment to feel its results on their tongues

Ramsha Waseem | Innovation Correspondent

October 6, 2026 2:14 p.m.

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Sneha Rao, a 27-year-old master’s student in design at Carnegie Mellon University, can trace the inspiration for her invention back to a 2020 article in the Wall Street Journal. In it, Eleanor Southwood, then the chair of the Royal National Institute of Blind People, said, “The dream is to buy any pregnancy test with the knowledge that it’s accessible.”

A few years later, Rao came across a Newsweek article that talked about Joanne Hewitson, a blind woman whose TikTok went viral in 2024. “She talked about never being able to take a pregnancy test alone,” says Rao. As most pregnancy tests available on the market provide visual results, Hewitson has to depend on her sister to read the results for her.

That article, says Rao, touched on something bigger than just pregnancy tests. “It was really about the systemic invisibility of blind and low-vision women in health care design more broadly,” she says.

“That stuck with me, because it wasn’t just about the inconvenience,” explains Rao. “It was about moments where privacy is a safety need.” As Hewitson suggested: What if a blind person had no one they could trust to help them with a pregnancy test, or were in an abusive relationship?

Followed by extensive research, Rao developed Tact: an edible lollipop that can help blind and low-vision women independently detect pregnancy. The user, if pregnant, will feel raised bumps on both sides of the flat lollipop—a reaction to hCG, a hormone that the body produces during pregnancy.

The problem with current options on the market

Recent data from the U.S. Census Bureau’s American Community Survey reveals that nearly nine million people in the United States live with some kind of vision disability, including blindness. Of the total population living with vision impairment, women and girls account for 4.8 million, or 54 percent—disproportionate to the general population, which is 50.4 percent female.

“Pregnancy tests are inaccessible both because they must be read visually and because the packaging and instructions are often inaccessible,” says Stephanie Enyart, a disability rights leader and chief public policy and research officer at the American Foundation for the Blind. She explains that users need to be able to check whether the test has expired, understand the instructions and perform the test. “Most blind women cannot independently read pregnancy results because they rely on detecting lines or color changes,” Enyart says, “and even women with some usable vision struggle if the line is faint.”

Additionally, Enyart points out that a pregnancy result is wrapped up in really complex human emotions, and depending on an individual’s situation, it can evoke a mixture of joy, fear, worry and excitement.

Though people with vision impairment can use applications such as Be My Eyes, Seeing A.I. and Aira for visual assistance, they end up losing their privacy and autonomy at such moments. Such applications largely depend on the users providing photos or videos, which are then interpreted with the help of artificial intelligence or human assistance.

“Not being able to read the result independently forces us to give up our privacy and invite someone else into that sensitive moment,” Enyart says. “For many reasons, a woman might not want her partner or a family member, friend or a complete stranger to know a pregnancy result before she does.” The pregnant individual wants to be the person to decide how and when to share the news.

“That’s why I wanted to create something that focuses so much on privacy and helps them take control,” says Rao.

Designing an accessible pregnancy test

In January, under the guidance of Carnegie Mellon biomedical engineering expert Wayne Chung, Rao set out to develop Tact. The master’s student in design for interactions, a field that studies how people interact with products, technology and systems, investigated various approaches.

One of the early ideas that Rao considered was a universal reader that could work with standard pregnancy tests already on the market. It would read the result and convert it into a different format, magnifying the result window, or giving an audio or tactile readout. It was a way to add accessibility without redesigning the test itself. However, the proposed design was eventually rejected on the basis that any technology involved in the process, whether an app, device or server, would create a data trail.

“What really troubled me was privacy,” Rao says. “The moment you photograph a pregnancy test and send it anywhere, you’ve created a record. That image exists somewhere.” And for someone in a situation where their reproductive health needs to be completely private, she warns, that’s not a small thing.

“The whole point of Tact is that there’s no trace—and a tech-mediated approach was always going to leave one,” she asserts.

Moreover, a tech-enabled design would result in a single-use product, contributing to a rise in e-waste. “As designers,” she adds, “we have a responsibility to understand the life cycle of a product that we are designing.” Beyond its environmental impact, this version’s dependence on tech to read a visual result was merely an additional step and not a true solution to the problem.

Her advisor, Chung, encouraged her to consider the intersection of food and medicine. He pointed to spy and espionage products as a reference—tools designed to self-destruct, leave no trace and disappear after use. From there, she discovered edible options that achieve the same outcome: a device that gives a result and then ceases to exist. “That reframe was important,” says Rao.

Changing her course, Rao started to imagine an edible device that could detect hCG in saliva. “The premise was that if the result can be felt rather than seen, and if saliva can replace urine as the sample, the whole device can go in the mouth, be used and be consumed,” she explains. Human chorionic gonadotropin, or hCG, is a hormone that is only produced in the body nearly six to ten days after conception. “There’s enough research about how saliva can detect hCG and give you a 96 percent accurate result about whether you’re pregnant or not,” says Rao.

She explored edible sublingual films, or strips placed under the tongue, that would change shape or texture in response to hCG, as well as hollow forms, which were casings with an internal cavity containing a reactive material that would change the outer surface if hCG were detected. Then she settled on lollipops.

Rao also considered adding taste as an indicator for the lollipop design, but she quickly discarded the idea. “Taste carries connotations that would compromise the neutrality of the result,” she explains. For most people, a sweet taste typically signifies good news, while a bitter taste is associated with bad news. But a pregnancy can mean different things for different women. Using taste as an indicator could add psychological pressure on the individual to feel a certain way. Rao instead decided to leverage texture—a more neutral option—as an indicator.

“You don’t have to interpret them in any other way than a simple positive or negative result,” she adds.

As a next step, Rao then proceeded to test various textures for her lollipop design. She 3D-printed textures with different patterns or arrangements of bumps to ascertain the most comfortable and legible one. “A lot can happen with tactility,” she says, so she sought to identify a texture that’s easily “recognizable for people once they put it on their tongue or once it develops.” Eventually, she produced the top designs with gelatin to try them out.

“The idea right now is to be able to use gelatin, because you will be consuming it,” she explains. Gelatin appears to be the most promising material because of its properties and flexibility. With simple modifications of its concentrations, gelatin can produce a soft jelly to something much firmer or gummier. “It has capillary-wicking properties, meaning it can draw liquid through itself without any pumping, which is exactly what I needed to create such a compact test,” says Rao. Moreover, gelatin can be designed to dissolve, which aligns with the concept of a device disappearing after use. It is also food-safe, widely available and cheap.

While the physical aspects of Tact are complete, Rao is currently working to integrate the gelatin matrix with a hCG-binding DNA aptamer, which is a short single-stranded DNA engineered to recognize the presence of the hCG hormone.

With Tact, all one needs to do is pop the flat oval-shaped lollipop into their mouth. And if the hCG is present, the hCG-binding DNA aptamer reacts, and the surface of the lollipop produces raised bumps that the user can feel with their tongue. “If both sides swell, then it is a positive, and if you get swelling on only one side the test is negative,” explains Rao. However, if there isn’t any swelling at all, the test is invalid.

“The whole idea is that you can take this test anywhere,” the inventor says. “It is a starting point.” Like with every pregnancy test, the user is expected to confirm the results with doctors or health care providers.

Next steps for Tact

Enyart was delighted to learn about Tact. “It is really good that people are innovating and trying to make tests accessible to more women, and this certainly seems to be thinking outside of the box,” the disability rights leader says.

That said, she cautions that there will be questions about the timing and effectiveness of the device. “For example, women usually want to know as soon as possible, but there are differences in how hCG tests work,” she says. Typically, blood tests can give a result 7 to 10 days after conception, and urine tests can provide one in 12 to 14 days. Enyart questions whether a saliva test can report consistently reliable results on a similar timeline as existing home urine tests.

She further points out that tactile pregnancy test prototypes, like the Royal National Institute of Blind People’s urine-stick test that displays results in silicone bumps, have previously made it to the news, but to her knowledge never to the market. Similarly, during the Covid-19 pandemic, the National Institutes of Health funded a project through RADx Tech to produce accessible diagnostic tests for people with visual impairments. However, Enyart notes, “Adhering to these best practices is voluntary, so we can see how even when there is information on accessibility, accessibility improvements don’t always make it to market.”

She adds, “Manufacturers may explore providing braille on boxes or redesigning the test device, but in the absence of a requirement, they may not do so if it adds cost or complexity to the manufacturing process.”

But Rao is just getting started. “I understand it would be difficult for a buy-in to happen, but I think Tact has promising factors,” she says. Visual pregnancy tests have decades of trust, whereas an edible test will need to earn that same trust. “An edible diagnostic also sits between food safety regulation and medical device regulation,” an unusual combination, “which makes the institutional path slower and more complex,” she adds.

For Rao, the next steps are clinical testing and regulatory groundwork. The ultimate objective, she adds, is to license the technology or partner with an existing diagnostics manufacturer, so that Tact becomes a viable option.

Ramsha Waseem is a freelance writer. Her work has appeared in BBC Travel, Dwell, Atlas Obscura and other media outlets.