A vibrating vest that writes messages on its wearer's back is being tested by researchers in the US. In future, it could be used to send important commands to soldiers or fire-fighters, warning them of imminent danger when ordinary radios cannot be used, for example.
The vest is made from black spandex and fastens around a person's lower torso with Velcro. An array of 16 small vibrating motors is embedded in the back of the vest and connects to a control unit on one side. This unit contains a wireless transceiver linked wirelessly to a controlling computer.
Commands sent from the computer are translated into patterns "displayed" – like Braille-on-the-back – by the vibrating motors.