  In this paper, we introduce 2DR, a single RFID tag which can seamlessly sense
two-dimensional human touch using off-the-shelf RFID readers. Instead of using
a two-dimensional tag array to sense human finger touch on a surface, 2DR only
uses one or two RFID chip(s), which reduces the manufacturing cost and makes
the tag more suitable for printing on flexible materials. The key idea behind
2DR is to design a custom-shape antenna and classify human finger touch based
on unique phase information using statistical learning. We printed 2DR tag on
FR-4 substrate and use off-the-shelf UHF-RFID readers (FCC frequency band) to
sense different touch activities. Experiments show great potential of our
design. Moreover, 2DR can be further extended to 3D by building stereoscopic
model.
