Vacuum Formed Spherical Triboelectric Architecture Overcoming Direction Constraints for 3D‐Omnidirectional Ultrasonic Energy Receiving

Ultrasound‐driven triboelectric nanogenerators (UD‐TENGs) have emerged as promising ultrasonic energy converters for underwater and biomedical applications. Nevertheless, prevailing planar UD‐TENGs exhibit pronounced directivity, which necessitates a prescribed deployment direction or complex ultrasound alignment strategies, and thus restricts both the output performance and practicality of these devices. This work introduces an ultrasound‐driven spherical triboelectric nanogenerator (UD‐STENG) that, for the first time, achieves 3D‐omnidirectional ultrasonic energy harvesting (UEH) via capacitive triboelectric technology. By conformally integrating triboelectric layers onto spherical surfaces through vacuum forming, the UD‐STENG establishes a spatially symmetric ultrasonic‐triboelectric interface and delivers near‐isotropic outputs regardless of the ultrasound incidence directions, generating average output powers from 0.42 to 2.92 mW over ultrasound intensities ranging from 0.05 to 3.0 W cm −2 . As a new UEH mode, the UD‐STENG maintains effective operation under dynamic harvesting conditions and can be simultaneously driven by ultrasound sources from multiple directions for enhanced output. In implantable demonstrations, the UD‐STENG operates independently of implantation directions and further supports practical functions, including real‐time wireless data transmission and on‐demand modulated pulse delivery. These advances expand the spatial operating window of UD‐TENGs and lay the foundation for next‐generation 3D triboelectric ultrasonic energy converters.