Three members of Harvard’s faculty will receive $500,000, “no strings attached,” as recipients of the prestigious MacArthur Fellowships.

The 24 winners of this year’s awards ranged from a 22-year-old MIT math professor who has studied the computational geometry of Tetris to a biomedical engineer who employs the biophysics of noise to enhance motor control to a modern day blacksmith.

With this year’s awards, the total number of Harvard faculty members who have garnered the so-called “genius grant” climbs to 38.

Unlike many other academic awards, there is no application procedure and candidates do not know they’re being considered until they’ve won.

“The call comes out of the blue and can be life-changing,” said Jonathan F. Fanton, president of the MacArthur Foundation, which sponsors the awards.

For this year’s winners, the call came on Sunday.

“[I said], ‘Whoa! Is it me? Are you sure you didn’t get the name wrong?’” recalled Xiaowei Zhuang, an assistant professor of chemistry and chemical biology who received one of this year’s fellowships.

A pioneer of the emerging field of biophysics, Zhuang has studied the interactions of individual molecules and used that research as the basis for examining the mechanism of viral membrane fusion with host cells.

Research of this type may shed light on the basic biology of infection and help to identify possible targets for therapeutic intervention in diseases such as AIDS and hepatitis, the MacArthur Foundation said in a press release.

In a statement, Dean of the Faculty of Arts and Sciences William C. Kirby lauded Zhuang’s research.

“She practices science with a remarkable versatility and originality,” he said.

Zhuang said she does not yet know how she will use the money, but plans to save it for a “high risk, high reward project” that is not easily funded.

“I will use it for a future good idea that I have,” she said.

Nawal Nour, an instructor in obstetrics, gynecology, and reproductive biology at Harvard Medical School (HMS), was delivering a baby when she learned that she had won one of this year’s prizes, according to a University press release.

In addition to her position as an instructor at HMS, Nour is the founder and director of the African Women’s Health Practice at Brigham and Women’s Hospital.