SleepSense: Smart Pillow With Pressure-Sensitive FBG-Embedded Silicone Buttons

Sleep quality plays an essential role in human health and has become an index for assessing physical health. Here, a pressure-sensitive, noninvasive, and comfortable smart pillow was developed based on an FBG sensor array to monitor head movements in real time during sleep. The FBG array was embedded in the polydimethylsiloxane (PDMS)-based silicone button for improved pressure sensitivity and durability. The sensitivity of the pressure sensor was further optimized by modifying the structure of the button bulge and the thickness of the second layer. Both real-time monitoring of head position in a static state and head movement trajectory in a dynamic sleep state are realized. Finally, the fabricated sensor array was used for respiratory rate (RR) monitoring, with potential applications in personal healthcare diagnosis. This work not only provides a viable sensing device for sleep monitoring, but could also be extended to real-time monitoring of some diseases, such as brain diseases and cervical spondylosis, in the future.