All-Electrospun Triboelectric Nanogenerator Incorporating Carbon-Black-Loaded Nanofiber Membranes for Self-Powered Wearable Sensors

Triboelectric nanogenerators (TENGs) are capable of sustainably powering wearable sensors by harvesting diverse forms of ambient mechanical energy. Nevertheless, the material and structural designs of friction layers have significant impacts on the performance of TENGs. Electrospun nanofibers can enhance the electrical performance of wearable TENG because of their large specific surface area and porosity. Herein, the free-surface electrospinning technique was used to prepare the positive and negative friction layers with special structures of TENGs. The porous nanofiber membrane (NFM) of polylactic acid (PLA)/chitosan (CS)/aloin with good biocompatibility was used as the positive friction layer of TENGs. Furthermore, a certain amount of carbon black (CB) nanoparticles (NPs) were loaded into thermoplastic polyurethanes (TPU) to prepare beaded NFMs (BNFMs), which helped to improve the hydrophobicity and charge storage capability of the negative friction layer. The morphology of BNFMs with various CB contents and their electrical output performances as negative friction layers were compared, respectively. It was found that the BNFMs could deform under different pressures to enhance the contact area and electrical output of TENG. Moreover, the BNFMs loaded with CB can not only increase their surface roughness but also enhance the charge transfer rate and storage capacity of the friction layer. This provided TENG with good electrical output, high stability, and durability, as well as great application potential in harvesting various types of biomechanical energies. In addition, the proposed all-electrospun TENG had better flexibility, wearing comfort, and fabricating ease, which could be adhered to the human body for sensing human motion when embedded into textiles.