As long as there have been computers, people have been looking for novel ways of interacting with them. We are all familiar with the keyboard, touchscreen, and mouse, but there are also much more exotic devices emerging from the research world that are designed to provide a more intuitive user experience. One of the latest to emerge is a capacitive sensor affixed to the eyelid that can detect blinking motions.
Eslucent, created by researchers from Cornell University's Hybrid Body Lab, is a sensor built on top of an existing cosmetic product called an eyelid sticker. Eyelid stickers are clear adhesive strips that are placed on the eyelid to create a temporary crease. The team added a conductive layer on top of an eyelid sticker, which registers a change in capacitance when a user opens or closes their eye. When open, Eslucent comes in contact with the inner skin of the eyelid crease, thereby increasing capacitance. Conversely, closing the eye breaks that contact and capacitance values are decreased.
When getting into the details of retrieving that sensor data, this clean and simplistic design starts to get a bit messy. A conductive thread sewn into the eyelid sticker runs across the side of the head and behind the ear. A TinyDuino microcontroller with a Bluetooth module receives the sensor input and wirelessly transmits it to the device to be controlled.
A study of 14 participants found that the blink detection algorithm achieved an average precision of 90% in recognizing intentional blinks.
The researchers included an art layer to hide the sensor as much as possible. However, with the wire running to a microcontroller behind the ear, the device looks cumbersome to wear and not very socially acceptable. Perhaps miniaturization of the relevant technologies will alleviate these issues in the future. Yet, you still may find yourself in some awkward spots if you have a habit of winking at everyone around you.