Technologies like NFC, RFID and QR codes are quickly becoming a normal part of everyday life, and now a group from Carnegie Mellon University has a fresh take on close-quarters data it calls acoustic barcodes. It involves physically etching a barcode-like pattern onto almost any surface, so it produces sound when something's dragged across it -- a fingernail, for example. A computer is then fed that sound through a microphone, recognizes the waveform and executes a command based on it. By altering the space between the grooves, it's possible to create endless unique identifiers that are associated with different actions.
It's easy to see how smartphones could take advantage of this -- not that we recommend dragging your new iPhone over ridged surfaces -- but unlike the technologies mentioned earlier, not all potential applications envisage a personal reading device. Dot barcodes around an area, install the sound processing hardware on site, and you've got yourself an interactive space primed for breaking freshly manicured nails. We're pretty impressed by the simplicity of the concept, and the team does a good job of presenting scenarios for implementing it, which you can see in the video below. And, if you'd like to learn a little more about the idea or delve into the full academic paper, the source links await you.