Researchers at the University of Waterloo in Canada have developed a novel hand-based input technique called Tip-Tap that amazingly requires no batteries.
The wearable device uses a series of three custom RFID tags on both the thumb and index finger with half an antenna on each digit. When the fingertips are touched together, a signal is sent to the computer indicating where the thumb and index finger intersect, which is mapped as a position on a 2D grid.
Usability experiments were carried out using an Arduino Mega, with both on-screen visual feedback and without. Possible applications could include the medical field, where Tip-Tap can be added to disposable gloves enabling surgeons to access a laptop without dictating inputs to an assistant or sterilization issues.
We describe Tip-Tap, a wearable input technique that can be implemented without batteries using a custom RFID tag. It recognizes 2-dimensional discrete touch events by sensing the intersection between two arrays of contact points: one array along the index fingertip and the other along the thumb tip. A formative study identifies locations on the index finger that are reachable by different parts of the thumb tip, and the results determine the pattern of contacts points used for the technique. Using a reconfigurable 3×3 evaluation device, a second study shows eyes-free accuracy is 86% after a very short period, and adding bumpy or magnetic passive haptic feedback to contacts is not necessary. Finally, two battery-free prototypes using a new RFID tag design demonstrates how Tip-Tap can be implemented in a glove or tattoo form factor.