Triboelectric Nanogenerator-Enabled 3D Microporous Polydimethylsiloxane-Graphene Oxide Nanocomposite for Flexible Self-Powered Humidity Sensing Applications

The imperative to meet the energy needs of contemporary electronic devices has spurred extensive exploration into self-powered systems. Given the anticipated ubiquity of sensor networks in future cities, a novel battery-free sensing paradigm, rooted in triboelectric nanogenerators (TENG), has gained prominence. Utilizing mechanical energy otherwise wasted daily for electricity generation presents a promising alternative to conventional sensors. Embedding the sensing electrode within the TENG structure enables the creation of gas sensors suitable for portable and wireless applications. This study focuses on fabricating a 3D microporous sponge of polydimethylsiloxane (PDMS) using sugar cubes and graphene oxide (GO) nanosheets. Leveraging the hydrophilic properties of the GO enhances moisture absorption, elevating the humidity sensor's responsivity. In addition, the porous structure not only improves sensitivity to high humidity but also mitigates surface saturation issues prevalent in nonporous sensors. The porous self-powered sensor, composed of PDMS with 0.5 wt% of GO, exhibits a response of up to 2500%, quantified as ((Delta V/V) x 100%), to relative humidity changes from 20% to 99%. Furthermore, the response and recovery times stand at 1.2 and 2.3 s, respectively. These findings underscore the feasibility of integrating TENG electrodes, utilizing a porous PDMS-GO nanocomposite, to create various types of integrated gas sensors. A 3D microporous structure of polydimethylsiloxane/graphene oxide (GO) has been utilized as an active humidity sensor. This structure facilitates improved moisture absorption, which is further enhanced by the inclusion of GO. The sensor's high moisture absorption capacity prevents saturation at high humidity levels while maintaining excellent responsiveness. The porous structure enables the development of a flexible, lightweight, and portable sensor.image (c) 2024 WILEY-VCH GmbH