3D Electronic Glasses

Multifunctional Smart Electronic Eyeglasses

Three-dimensional-printed, personalized, multifunctional electronic eyeglasses (E-glasses), not only to monitor various biological phenomena but also to propose a strategy to coordinate the recorded data for active commands and game operations for human−machine interaction (HMI) applications. Soft, highly conductive composite electrodes embedded in the E-glasses enable us to achieve reliable, continuous recordings of physiological activities. UV-responsive, color-tunable lenses using an electrochromic ionic gel offer the functionality of both eyeglass and sunglass modes, and accelerometers provide the capability of tracking precise human postures and behaviors. Detailed studies of electrophysiological signals including electroencephalogram and electrooculogram demonstrate the feasibility of smart electronic glasses for practical use as a platform for future HMI systems.

The prototype eyewear was developed by a team led by Assoc. Prof. Suk-Won Hwang, from Korea University’s KU-KIST Graduate School of Converging Science and Technology.

Featuring a 3D-printed frame, the “e-glasses” incorporate flexible electrodes located near the wearer’s ears and eyes. The former sensors serve as an electroencephalogram (EEG), monitoring electrical activity in the brain, while the latter function as an electrooculogram (EOG), which tracks eye movements. Both types of data are wirelessly transmitted from the glasses for processing.

In lab tests, the EEG was successfully used to record volunteers’ alpha rhythms, which could in turn be used to monitor their health. The EOG data, on the other hand, allowed participants to play a brick-stacking video game simply by moving their eyes. Such a feature might conceivably find use in hands-free control of computers, or in assistive technologies designed for the physically challenged.

The e-glasses additionally have an ultraviolet light sensor on the side of one arm, which measures the intensity of incoming UV rays. When the sunlight gets bright enough, that sensor triggers a UV-blocking gel inside the lenses to get darker – thus temporarily turning the glasses into sunglasses.

Finally, the e-glasses also have an accelerometer in the same arm as the light sensor. It is able to track the user’s posture and gait and can detect when they fall down. This means that the glasses could be used in virtual reality systems, or to monitor people such as seniors, automatically sending alerts if mishaps are detected.

Diverse applications of the smart E-glasses as below:

1. Optical image and a graphical process diagram of sunlight-responsive eyeglasses.
2. Measured amount  of  sunlight  (black)  throughout  the day using the UV sensor integrated into the smart E-glasses, and  the associated preset voltages (blue) that drive the glass  lens  to  change the color to dark blue.
3. Experimental results on changes in transmittance of the eyeglasses under external UV (@365 nm, red region) and fluorescent (white region) light sources.
4. Characterizations of a motion-detecting system via a triaxial accelerometer built on the E-glasses (black, X axis; red, Y axis; and blue, Z axis).
5. Signal summation of vector components in a 3D system of coordinates while the position of the accelerometer moved from its original location (0,0,0) to the assigned site (2,1,2) (black, X axis; red, Y axis; blue, Z axis; and purple, sum).
6. Measurements of various static and dynamic body motions using the E-glasses with a built-in accelerometer.

Materials, system design and applications reported here represent a technological platform of a multifunctional wearable system in which each component not only performs assigned roles in corresponding environments but also operates as a well-organized system to determine particular situations or unexpected accidents in comprehensive and systematic manners. Optimized electrical and mechanical properties  of  soft conductive electrodes provide acquisition of reliable, real- time  electrophysiological  information,  enabling manipulation of human−computer interactions through the obtained  signals.

The ability to transform into sunglasses and to integrate UV monitors and accelerometers reveal the versatility and flexibility of the system to integrate diverse functions. These overall results will provide technical insights into the associated technologies and industries such as digital healthcare and virtual reality (VR) /augmented reality (AR).

For more information contact Suk-Won Hwang − KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul dupong76@korea.ac.kr.