Highly-Sensitive Skin-Attachable Eye-Movement Sensor Using Flexible Nonhazardous Piezoelectric Thin Film

Nam In Kim, Jie Chen, Weijie Wang, Mina Moradnia, Sara Pouladi, Min Ki Kwon, Ja Yeon Kim, Xiaohang Li, Jae-Hyun Ryou

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


Accurate and continuous monitoring of eye movements using compact, low-power-consuming, and easily-wearable sensors is necessary in personal and public health and safety, selected medical diagnosis techniques (point-of-care diagnostics), and personal entertainment systems. In this study, a highly sensitive, noninvasive, and skin-attachable sensor made of a stable flexible piezoelectric thin film that is also free of hazardous elements to overcome the limitations of current computer-vision-based eye-tracking systems and piezoelectric strain sensors is developed. The sensor fabricated from single-crystalline III-N thin film by a layer-transfer technique is highly sensitive and can detect subtle movements of the eye. The flexible eye movement sensor converts the mechanical deformation (skin deflection by eye blinking and eyeball motion) with various frequencies and levels into electrical outputs. The sensor can detect abnormal eye flickering and conditions caused by fatigue and drowsiness, including overlong closure, hasty eye blinking, and half-closed eyes. The abnormal eyeball motions, which may be the sign of several brain-related diseases, can also be measured, as the sensor generates discernable output voltages from the direction of eyeball movements. This study provides a practical solution for continuous sensing of human eye blinking and eyeball motion as a critical part of personal healthcare, safety, and entertainment systems.
Original languageEnglish (US)
Pages (from-to)2008242
JournalAdvanced Functional Materials
Issue number8
StatePublished - Dec 8 2020

Bibliographical note

KAUST Repository Item: Exported on 2021-11-21
Acknowledged KAUST grant number(s): OSR-2017-CRG6-3437.02
Acknowledgements: The work at the University of Houston is partially supported by the Advanced Manufacturing Institute (AMI) at the University of Houston, the Texas Center for Superconductivity at the University of Houston (TcSUH), King Abdullah University of Science and Technology (KAUST), Saudi Arabia (Contract No. OSR-2017-CRG6-3437.02), and the National Science Foundation under Grant No. 1842299 (Electrical, Communications and Cyber Systems (ECCS)).

ASJC Scopus subject areas

  • General Chemical Engineering
  • Electronic, Optical and Magnetic Materials


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