COLLEGE PARK, Md.—Maple tree seeds (or samara fruit) and the spiraling pattern in which they glide to the ground have delighted children for ages and perplexed engineers for decades. Now ...

Maple tree seeds (or samara fruit) and the spiraling pattern in which they glide to the ground have delighted children for ages and perplexed engineers for decades.

Photo: The maple seed device compared to actual samara seeds. (Photo by Eric Schurr/A. James Clark School of Engineering, U-Md.) Maple tree seeds (or samara fruit) and the spiraling pattern in ...

The enigmatic maple tree seeds (or samara fruit) - and the unique spiraling pattern with which they glide to the ground - have intrigued children and engineers for decades.

Northwestern University says these are the world's smallest human-made flying structures, and they could be used for monitoring the environment, population surveillance or disease tracking.

Northwestern University says these are the world's smallest human-made flying structures, and they could be used for monitoring the environment, population surveillance or disease tracking.

Northwestern University says these are the world's smallest human-made flying structures, and they could be used for monitoring the environment, population surveillance or disease tracking.

Northwestern University says these are the world's smallest human-made flying structures, and they could be used to monitor the environment, population surveillance or disease tracking.