Scratch Input: Creating Large, Inexpensive, Unpowered and Mobile Finger Input Surfaces

Authors:
Chris Harrison, Scott E. Hudson (Carnegie Mellon University)

Summary:
Scratch Input is a sensor that detects the sound of a fingernail being dragged across different surfaces. The reason for such a sensor is to allow for the addition of a finger input device (gesture recognition). The device (which fits into a modified stethoscope) is small enough to be added to mobile devices. The sensor can be placed onto any solid surface and detect the unique high frequency of scratching (listed as 3000Hz or more). In this paper, the authors also go over some examples of when Scratch Input could be useful. One of which comes from the case that a cell phone is equipped with the device and is resting on a table. When an incoming call is received, the user performs a certain gesture on the tabletop and the phone takes the call on speakerphone. Another example involved placing the device on a wall and using different gestures on said wall to manipulate the playback of music. The authors found that, while testing on tables during a user study, people were able to accurately perform a set of six gestures with an average accuracy of 89.5%. They concluded that their product is both accurate and easy to use.

Some gestures

Discussion:
These guys seem to like making cheap little gadgets (my previous blog was over another such product). I wonder what it is that drives them to do this kind of research and development? Anyway, just like their last paper, this seems like a cool idea. Being super super lazy and just scratching or tapping on the wall or a table to get stuff done would rock! If I want my computer to start torrenting episodes of Archer, all I have to do is sketch out a big A. If I want my cell phone to call Dominos, but I don't want to have to reach over and pick it up, I can draw a D and then yell my order at the phone. It's every lazy person's dream!