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Tiny battery-free ultrasonic tags for smart homes (Level A1) — a woman sitting in a chair with a tablet

Tiny battery-free ultrasonic tags for smart homesCEFR A1

29 Apr 2026

LevelA1
A2
B1
B2

Adapted from Georgia Tech, Futurity • CC BY 4.0

Photo by Terry Granger, Unsplash

Level A1 – Beginner
2 min
78 words
  • Researchers made tiny metal tags for smart homes.
  • The tags are smaller than a coin and cheap.
  • They do not need a battery or power plug.
  • A moving part hits the tag and makes a sound.
  • The sound is ultrasonic so people cannot hear it.
  • A nearby wearable device can hear and record it.
  • Each tag makes a different high sound.
  • Tags can count actions and help monitor everyday things.
  • They are quiet and protect privacy at home.

Difficult words

  • tag — small label or object used for identification
    tags
  • wearable device — electronic item you wear to record data
  • ultrasonic — sound at a very high frequency people cannot hear
  • battery — a small power source for electronic devices
  • monitor — to watch or check something over time
  • privacy — keeping personal information private at home

Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.

Discussion questions

  • Do you have a wearable device?
  • Would you like quiet devices that monitor things at home?
  • Is privacy important in your home?

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