Abstract: A fabrication process is disclosed for the production of flexible triboelectric nanogenerator (TENG) fiber, which can comprise a copper core surrounded by a silicone cladding. The TENG fibers are fabricated using a coaxial micro-extrusion process that enables 2D and 3D constructs to be fabricated with the fibers via 3D printing on both stationary and moving substrates to form mechanosensors as membranes, meshes, and hollow 3D structures. The mechanosensors can be integrated into wearable items for human activity monitoring, or can be formed on organs for organ monitoring, e.g., monitoring of perfused organs. The mechanosensors can be integrated into facemasks and uses for silent speech recognition, such as words mouthed in the absence of sound production by the speaker. The mechanosensors are self-powered and have high stretchability.