In her junior year at Stern Undergraduate College, Sophie Frank (BS ’17) had an epiphany. She had recently returned from a course experience in India, where her twin passions for activism and social entrepreneurship had begun to percolate.

Pre-pandemic India suffered from the world’s worst pollution, yet, Frank noted, few people wore masks. With such hot weather, and with motorbikes the popular mode of transportation, masks were impractical. The need for something people would wear was obvious.

“A sixth of the world’s population lives in India,” she noted, “and if you could come up with a wearable device to filter the air, at even a dollar each, you’d not only be helping people, you’d be a billionaire.”

Frank wanted the imagined devices to be ornamental as well as functional. The Stern junior came up with an answer: a filter that people wore in their nostrils: “Kind of like nasal jewelry, I thought at first,” Frank recounted. An athlete herself, she determined the device should allow for exercising, drinking, talking, and socializing with minimal interference.

Thus, Resprana was born. Its business plan was the new venture winner in Stern’s $300K Entrepreneurs Challenge, which awarded $75,000 to develop the idea. She set about to realize the plan, working with “some of the best design minds in NYC,” and established a relationship with a top filter innovation firm from New Zealand, Revolution Fibres.

The first product, called Duo, consists of a pair of in-nostril, replaceable air-filter cartridges encased in medical-grade moldable silicone and fitted with a sleek steel, titanium, or gold ring. The prototype launched on Indiegogo in summer 2020 and, having partnered with a sourcing supplier to help set up manufacturing and logistics, the team is currently in production, making Duo available to backers.

Duo filters out pollution, pollen, dust, smog, and smoke, and some viral particles, but not Covid-19 or other viruses. The filters are most heavily focused on breathability and comfort and filter at a rate of nearly 100 percent for particles such as dust, sand, larger viral droplets, and allergens; 85 percent for pollution particles; and about 60 percent for the smallest particles associated with Covid-19. “We are constantly developing new filters and improving our breathability and filtering efficiency,” Frank pointed out.