Self-powered smart pillow tracks sleep

Many people who struggle to get enough sleep could benefit from monitoring their sleep, but they have limited options for doing so. In a new study in ACS Applied Materials & Interfaces, one team describes a potential solution: a self-powering smart pillow that tracks the position of the head.

According to a report on the technology in offgridenergyindependence.com, studies have linked chronic lack of sleep to physical ailments, such as diabetes and heart disease, as well as mental health issues. There have been just two primary options for helping people with sleep issues: they can take a sleep test conducted in a medical facility, or they can use an app through a smartphone or smart watch. The app is more convenient, but it is also less accurate. 

Various teams have begun developing new sleep monitoring systems using triboelectric nanogenerators (TENGs). These self-powering systems have taken the form of eye masks, belts, patches and even bed sheets. Chinese scientists Ding Li, Zhong Lin Wang and their colleagues wanted to adapt this approach to create a less restrictive, more comfortable version that focuses on the movement of the head during sleep. 

To construct this new smart pillow, the researchers formulated a flexible, porous polymer triboelectric layer. Movement between the head and this layer changes the electric field around nearby electrodes, generating a current. They strung together several of these self-powering sensors to create a flexible and breathable TENG (FB-TENG) array that can be placed atop an ordinary pillow. This system could generate voltage that corresponded to the amount of applied pressure, and it could track the movement of a finger tracing out letters. 

This smart pillow could have uses beyond tracking sleep, the researchers say, such as to monitor patients with diseases that affect the movement of the head, and it could be adapted to warn about a user at risk of falling out of bed. 

The authors acknowledge funding from the National Key Research & Development Project from the Ministry of Science and Technology of the People’s Republic of China and the National Natural Science Foundation of China.