New 'smart' paper can respond to gestures

Scientists, including one of Indian-origin, have created 'smart' paper with sensing capabilities that can respond to gesture commands and connect to the digital world.

The method relies on small radio frequency (RFID) tags that are stuck on, printed or drawn onto the paper to create interactive, lightweight interfaces that can do anything from controlling music using a paper baton, to live polling in a classroom.

The technology - PaperID - leverages inexpensive, off-the-shelf RFID tags, which function without batteries but can be detected through a reader device placed in the same room as the tags.

Using the technology, connecting real-world items such as a paper airplane or a classroom survey form to an Internet of Things environment may be possible, researchers said.

"These little tags, by applying our signal processing and machine learning algorithms, can be turned into a multi-gesture sensor," said lead author Hanchuan Li, a doctoral student at University of Washington.

Each tag has a unique identification, so a reader's antenna can pick out an individual among many. These tags only cost about 10 cents each and can be stuck onto paper.

Alternatively, the simple pattern of a tag's antenna can also be drawn on paper with conductive ink.

When a person's hand waves, touches, swipes or covers a tag, the hand disturbs the signal path between an individual tag and its reader.

Algorithms can recognise the specific movements, then classify a signal interruption as a specific command.

For example, swiping a hand over a tag placed on a pop-up book might cause the book to play a specific, programmed sound.

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 interesting aspect of PaperID is that it leverages commodity RFID technology thereby expanding the use cases for RFID in general and allowing researchers to prototype these kind of interactive systems without having to build custom hardware," said Shwetak Patel, professor at University of Washington.

They also can track the velocity of objects in movement, such as following the motion of a tagged paper conductor's wand and adjusting the pace of the music based on the tempo of the wand in mid-air.

The researchers chose to demonstrate on paper in part because it is ubiquitous, flexible and recyclable, fitting the intended goal of creating simple, cost-effective interfaces that can be made quickly on demand for small tasks.

"Ultimately, these techniques can be extended beyond paper to a wide range of materials and usage scenarios," said Alanson Sample from Disney Research.