Commercial RFID tag stickers – which are powered by incident RF energy and don't need batteries and cost about 10 cents each – can be attached to paper and allow users to draw with conducting ink and customize their own tags. Antennas can be printed using silver nanoparticle inks and the adapted paper can interact with local computing resources.
The researchers developed different interaction methods to adapt RFID tags depending on the type of interaction that the user wants to achieve. For example, a simple sticker tag works well for an on/off button command, while multiple tags drawn side-by-side on paper in an array or circle can serve as sliders and knobs.
The technology is called PaperID and applications can vary from using pop-up books to wirelessly trigger sound-effects, to capturing the content of paper forms. The researchers include the example of using a paper baton to control the tempo of music.
It works by monitoring changes in the low-level parameters of the RFID channel communication. The low-level parameters include: signal strength, signal phase, channel number and Doppler shift. The use of multiple RFID tags in close proximity is used to create a number of interactions and gesture recognition primitives that can be used as building blocks for higher order interactions.
The team has developed machine-learning software to identify more complex gestures and these higher-order interactions include, cover, touch, sliding, turning, swiping, tag movment and hand waving.
The PaperID technology can be applied other media and surfaces to enable gesture-based sensing capabilities. The researchers chose to demonstrate on paper in part because it’s ubiquitous, flexible and recyclable, fitting the intended goal of creating simple, cost-effective interfaces that can be made quickly on demand for small tasks.
The researchers presented their work o May 12 at Association for Computing Machinery's CHI 2016 conference in San Jose, California.
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