2, Kyung Hee University, Yongin, , Korea (the Republic of)
Triboelectric nanogenerators (TENGs) are one of the energy harvesters that generated by common mechanical energy. These devices show outstanding performances by light weight, eco-friendliness, low cost, and portability. Nonetheless, the commercialization of TENGs meets its fabrication method’s requirements such as cost-effective, simple processing, scalable. Even these are fabricated in textile-type compatible with a various textile-type devices. In this study, we report for the first time, the layer-by-layer (LbL) assembly of graphene-polymer multilayers for cost-effective, scalable, simple-processing, and wearable TENGs. We could fabric TENGs with graphene-polymer multilayers on flexible polymer substrates with flat, undulated, and textile surfaces by LbL technique. Graphene-polymer multilayers roles as a positive triboelectric material and as an electrode, where the polymer substrate role as a negative triboelectric material. We assemble targeted number of graphene-polymer bilayers and its properties are analyzed by using the morphological and electrical properties. Due to advantages of LbL technique such as simple-processing, scalable, graphene-polymer multilayers could be uniformly deposited on undulated 3D surfaces, even on large-scale fabric textiles. These LbL assembled graphene-polymer multilayers called graphene based-TENGs (G-TENGs) with high mechanical durability and outstanding triboelectric performances. As a result, textile sample with graphene-polymer multilayers shows wearable and scalable textile-based G-TENG (TG-TENGs). Due to dual roles of graphene-polymer multilayers, TG-TENGs operated in a single electrode mode with cost-effective and compatibility with textile products such as cloths, bags, etc. Advantages of LbL technique can enable the fabrication of TENGs on various types of substrates. Thus, LbL assembled G-TENGs have variety of applications such as portable personal microelectronic device (e.g., self-powered wireless sensors). The LbL assembled graphene-polymer multilayers show outstanding triboelectric performances and high durability (over 20,000 times for bending and rolling) by cost-effective, scalable, and wearable G-TENG’s properties. A 3 BL graphene-polymer thin film shows the maximal output performance (~100 V and ~5 μA at 9 N) due to its suitable morphological and electrical properties. We expect LbL technique for G-TENG fabrication to be a powerful technique for the real-world commercial application of TENGs, particularly in the electronic textiles industry.