A Disney Research team proposed a new technology that is able to sense and recognize the different people touching a device. The technology is called capacitive fingerprinting, and it is the subject of a study called Capacitive Fingerprinting: Exploring User Differentiation by Sensing Electrical Properties of the Human Body. Capacititve fingerprinting is based on Swept Frequency Capacitive Sensing, an approach that Disney Research explored in a sensing technology called Touché.
Essentially, Touché takes note of user impedance over AC frequencies, and creates an impedance profile based on them. Such profile is unique, given that factors like an individual’s bone density and muscle mass and other electrical properties may alter the contents of the impedance profile. These impedance profiles may be used to connect a particular touch event or gestures to an individual user. In other words, the profile distinguishes the individuals that are touching the capacitive touchscreen during a given instance. This is made possible through “machine-learning classification and categorization algorithms .” However, Disney Research points out that the technology does not need instrumentation from the individuals or the environment.
By comparison, capacitive touch screen devices today are only able to sense multi-touch gestures by sensing different points of contact on the display.
Disney Research expects that the technology has potential uses in interactive design. For instance, it may be used for personalization. It may also be applicable in collaborative interaction like shared gaming. Lastly, it may be explored for security.
Disney Research shows a demonstration of capacitive fingerprinting in a digital drawing application that several users may share. Through the technology, each user is able to pick a color to use on the digital canvas. Each user is able perform an undo function for the gestures that one applied on the display.
The capacitive fingerprinting technology continues to be developed by its proponents, Chris Harrison of HCII and Carnegie Mellon University; Munehiko Sato of the University of Tokyo, and Ivan Poupyrev.