Gel-Based Stretchable Triboelectric Nanogenerators to Revolutionize Wearable Technology

By HospiMedica International staff writers
Posted on 20 Dec 2024

Image: An in-situ curing strategy to develop a stretchable, semi-transparent, and durable GPE-TENG (Photo courtesy of Pandey et al. (2024), Chemical Engineering Journal; DOI: 10.1016/j.cej.2024.156650)

Wearable technology, ranging from fitness trackers and smartwatches to medical sensors worn on the body, is revolutionizing our interaction with technology. As these devices gain in popularity, triboelectric nanogenerators (TENGs), which convert mechanical energy, such as body movement, into electrical energy, offer a way to power them without the need for batteries. Most TENGs in wearable applications use a triboelectric material attached to an electrode that conducts electrical current. However, one of the challenges has been finding flexible electrode materials that can move naturally with the human body. To solve this, researchers have developed a gel polymer electrode-based triboelectric nanogenerator (GPE-TENG). This device, described in research published in the Chemical Engineering Journal, is stretchable, semi-transparent, and durable, making it ideal for use in wearable sensor applications.

The research team from Dongguk University (Seoul, Republic of Korea) fabricated the device by pouring a gel mixture of polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) into an ecoflex mold. The gel is evenly spread and covered with another layer of ecoflex. A copper wire is connected to the gel to allow for electrical flow, and the entire assembly is cured at 70°C for 12 hours, ensuring a strong bond between the gel and the ecoflex layers. The resulting device is durable, flexible, and semi-transparent, generating electrical signals when tapped or stretched, with a peak power output of 0.36 W/m² at a load of 15 MΩ. During testing, the device was able to stretch up to 375% of its original size without damage, and it endured two months of bending, twisting, folding, and stretching without any signs of delamination or performance loss. As wearable technology becomes increasingly integral to daily life, the GPE-TENG could enable devices that monitor joint activity for rehabilitation or function as biometric systems in clothing, potentially allowing users to unlock smart doors or lockers.

“This work could revolutionize wearable technology by developing sustainable and flexible electronic devices with promising applications in human healthcare, rehabilitation, security systems, and secure biometric authentication systems,” said Professor Jung Inn Sohn from Dongguk University who led the research team.