When Allan Maman, a 17-year-old senior at Byram Hills High School in Armonk, New York, asked to stay after school and use the school's 3-D printer, his physics teacher was thrilled. The teacher would ...

Catherine Hettinger knew her invention — the fidget spinner — was working as she sat alone before a meeting with the vice president of Hasbro, one of the largest toy manufacturers in the world. “That ...