EditorialA red wristband, indicating that the wearer prefers low risk social interaction, in Manhattan on Dec. 19, 2021. (Sasha Maslov/The New York Times)
EditorialThe bracelet, a cuff with spiky transducers, has 24 speakers that emit ultrasonic signals when the wearer turns it on, at the University of Chicago in Illinois on Feb. 13, 2020. (Petra Ford/The New York Times)