Smart Pillow Based on Flexible and Breathable Triboelectric Nanogenerator Arrays for Head Movement Monitoring during Sleep

Abstract

Sleep quality plays an essential role in human health and has become an index for assessing physical health. Self-powered, sensitive, noninvasive, comfortable, and low-cost sleep monitoring sensors for monitoring sleep behavior are still in high demand. Here, a pressure-sensitive, noninvasive, and comfortable smart pillow is developed based on a flexible and breathable triboelectric nanogenerator (FB-TENG) sensor array, which can monitor head movement in real time during sleep. The FB-TENG is based on flexible and breathable porous poly­(dimethylsiloxane) (PDMS) with a fluorinated ethylene propylene (FEP) powder and exhibits pressure sensitivity and durability. The electrical output of the FB-TENG is further optimized by modifying the porous structure and the FEP powder. Combining the FB-TENG and the flexible printed circuit (FPC), a self-powered pressure sensor array is fabricated to realize touch sensing and motion track monitoring. The smart pillow is formed by laying the self-powered pressure sensor array on an ordinary pillow to realize real-time monitoring of the head position in a static state and head movement trajectory in a dynamic state during sleep. Additionally, the smart pillow also has an early warning function for falling out of bed. This work not only provides a viable sensing device for sleep monitoring but also could be extended to real-time monitoring of some diseases, such as brain diseases and cervical spondylosis, in the future. It is expected to introduce a practical strategy in the real-time mobile healthcare field for disease management.

Recent Progress of Triboelectric Nanogenerators for Biomedical Sensors: From Design to Application

“…The FB-TENG is made of pressure-sensitive and durable porous poly(dimethylsiloxane) (PDMS) with fluorinated ethylene propylene (FEP) powder. Kou et al proposed a practical sensing device for sleep monitoring that could be expanded in the future to real-time monitoring of certain disorders, including brain ailments and cervical spondylosis [ 130 ]. Figure 11 d shows a large-scale triboelectric nanogenerator with a flexible sleep sensor.…”

“…( b ) The use of the TES to monitor the body during sleep [ 129 ]. ( c ) Utilization of an FB-TENG array in the form of a smart cushion for the purpose of monitoring head movement [ 130 ]. ( d ) Self-powered source for a bendable sensor for tracking human sleep [ 131 ].…”

Ultrastretchable, Self-Healing Conductive Hydrogel-Based Triboelectric Nanogenerators for Human–Computer Interaction

“…However, the lack of highly stretchable electrodes severely restricts the development of flexible TENGs . Common electrodes for flexible triboelectric nanogenerators are (i) metals and its derivatives; ,, (ii) carbonaceous fillers; ,, (iii) conducting polymers; ,, and (iv) hydrogels, ,, etc. Metals and their derivatives, despite their excellent electrical conductivity, have limited stretchability .…”

Recent progress in flexible pressure sensors based on multiple microstructures: from design to application

“…3 Depending on the sensing mechanism, PSs can be classified into four types: piezoresistive, 4-6 capacitive, [7][8][9] piezoelectric, [10][11][12][13] and triboelectric sensors. [14][15][16][17] In addition, the more studied sensors include organic transistor sensors, [18][19][20][21] ion sensors 22,23 and hybrid response pressure sensors. 24,25 To meet the need for accurate signal transmission in wearable applications, pressure sensors require continuous improvement of key performance parameters such as sensitivity, dynamic range, detection limits, response/recovery time, and cycling stability.…”