Acoustruments for Adding Physical Controls to Smartphones by Using Plastic Tube

Touchscreen on smartphone is good for most occasions. However, it might not ideal for some situation. To resolve this issue, a group of researchers from Carnegie Mellon University and Disney Research has created a few series of accessories named Acoustruments.
The way that Acoustruments work is...
Acoustruments for Adding Physical Controls to Smartphones by Using Plastic Tube