More than 80 percent of women diagnosed with HIV contract the virus through heterosexual sex. A condom provides the best protection against HIV — but men aren’t always willing to wear them.

The female condom has been on the market since 1993. Unfortunately, it’s less familiar and more expensive than the male condom — and can make a rustling noise, prompting unfortunate comparisons to a wastepaper basket.

But researchers at the University of Washington in Seattle have come up with a new way for women to protect themselves against HIV and other sexually transmitted diseases. The method is not unlike a technology familiar to many women: the tampon.

Here’s how it works: An anti-HIV microbicide — a substance that can kill microbes as well as prevent HIV and other sexually-transmitted infections — is woven into fabric that can be inserted like a tampon before intercourse. Once inserted, the material dissolves, and the microbicide is absorbed into the vagina within six minutes.

It’s a vast improvement over gel and cream microbicides that leak, are messy or take too long to work.

That means women don’t have to apply it far in advance of having sex,” bioengineer Cameron Ball told NPR. “There’s a race between the anti-HIV microbicide to get to the tissue before the virus does. So the more quickly it dissolves, the better.”

Ball and fellow bioengineer Kim Woodrow published a paper about the new delivery mechanism in June in the journal Antimicrobial Agents and Chemotherapy.

Ball and Woodrow told NPR the key innovation is the fabric. Made using nanotechnology, it’s incredibly thin.

“It’s way better than any Egyptian cotton, high-count fabric that you could find,” Ball says. “Each thread is about 200 times smaller than a human hair.”

The fabric has been approved by the FDA, but some microbicides that could be used with it are still in clinical trials. It will be 10 years before the technology is commercially available.

In the meantime, researchers are studying possible shapes for the delivery mechanism. “It’s a matter of giving women enough choices and options of what products are available and how they are used,” Ball told NPR. “So you meet the needs of as many women as possible.”

While tampons are familiar to many women, some studies suggest populations at the highest risk of HIV infection don’t use them.

Twenty-seven percent of all women in the United States are black or Hispanic, but these women account for 79 percent of HIV cases among women. Poverty can also increase risk factors for HIV transmission.

A 2012 study of low-income women aged 18 to 35 published in the journal of Pediatric and Adolescent Gynecology found that black and Latina women were less likely to use tampons than white women. The sample size of the study was small – only 165 women – but the results revealed stark differences. While 71 percent of white women used tampons, only 29 percent of black women, 22 percent of English-speaking Latina women and 5 percent of Spanish-speaking Latina women did.