Luis von Ahn, a consulting professor in Carnegie Mellon University's Computer Science Department and co-founder and CEO of the language-learning platform Duolingo, is among 175 academic inventors elected as 2020 fellows of the National Academy of Inventors (NAI).

As a CMU graduate student and later faculty member, von Ahn helped develop the modern CAPTCHA, a tool that enables websites to distinguish between bots and real people. He also invented reCAPTCHA, a variation that digitized books as people solved each CAPTCHA puzzle.

Later, he and his former student, CMU alumnus Severin Hacker, invented Duolingo, a free service for learning languages that now boasts more than 300 million users worldwide. Last year, Duolingo became Pittsburgh's first "unicorn" — a tech startup valued at more than $1 billion.

"Throughout my career, I've been passionate about using invention and technology to make a positive difference in the world — previously with reCAPTCHA and now with Duolingo," von Ahn said. "It is a great honor to be elected an NAI fellow and represent Carnegie Mellon alongside many other talented academic inventors who have created lasting impact."

The NAI Fellows Program highlights academic inventors who have demonstrated a spirit of innovation and contributed to inventions that have made a tangible impact on quality of life, economic development and the welfare of society. Election to NAI fellow is the highest professional distinction accorded solely to academic inventors.

Von Ahn was an early pioneer of crowdsourcing, initially by devising online games that harnessed game play to accomplish tasks. His ESP Game, for instance, assigned descriptive labels to unlabeled images that had been uploaded to the web. Google purchased the ESP Game and later reCAPTCHA, which also took advantage of crowdsourcing.

Duolingo had its own crowdsourcing angle — people learning a language with the app would translate texts for Duolingo customers as they completed practice exercises. Von Ahn and Hacker emphasize that their larger goal is to help millions of people learn English or another language that they need to compete for jobs but cannot afford without the free Duolingo app.

Von Ahn, who earned his Ph.D. in computer science at CMU in 2005, has received numerous awards, among them the 2018 Lemelson-MIT Prize for invention, a 2006 MacArthur "Genius" Fellowship and the Association for Computing Machinery's Grace Hopper Award. As a faculty member, he held the Nico A. Habermann development chair in computer science. He received the Presidential Early Career Award for Scientists and Engineers, accepted Sloan Research and Packard fellowships, and was named to MIT Technology Review's prestigious TR35 list of top young innovators.

The 2020 class of NAI fellows will be inducted in June at the NAI annual meeting in Tampa, Florida. The class collectively holds more than 4,700 U.S. patents and represents 115 research universities and governmental and nonprofit research institutes worldwide.