# Dual-Electrodes PMUTs on Glasses for Wearable Human Blink Monitoring

## TL;DR

This paper introduces a wearable glasses device using dual-electrode PMUTs to monitor blinking for applications like safety and health.

## Contribution

A novel dual-electrode PMUT design integrated into glasses for non-contact blink monitoring using standard fabrication processes.

## Key findings

- The device uses TOF pulse-echo and unsupervised learning to detect blink states accurately.
- It is fabricated using cost-effective standard MEMS processes, enhancing wearability and biosafety.
- The design offers improved comfort, privacy, and reliability compared to traditional eye monitoring methods.

## Abstract

Blink monitoring has demonstrated significant application value in fields such as safety assessments, medical monitoring, and intelligent technologies. Traditional eye monitoring methods are limited by restricted adaptability, insufficient comfort, or potential risks. MEMS-based ultrasonic technology, as a non-contact approach, has garnered attention due to its strong environmental adaptability, privacy, and security. However, existing designs require high-sensitivity processing circuits and are incompatible with standard fabrication processes. This work proposes a dual-electrode piezoelectric micro-mechanical ultrasonic transducer (PMUT) design based on aluminum nitride (AlN) piezoelectric thin films, integrated into a glasses device to enable real-time blink activity monitoring. The design successfully identifies blink states through time-of-flight (TOF) pulse-echo technology and dynamic unsupervised learning methods. Fabricated using cost-effective standard multi-user MEMS processes, this device offers distinct merits in terms of wearability comfort, information security, biosafety, and reliability.