ABSTRACT: Human-machine interfaces are essential components between various human and machine interactions such as entertainment, robotics control, smart home, virtual/augmented reality, etc. Recently, various triboelectric-based interfaces have been developed toward flexible wearable and battery-less applications. However, most of them exhibit complicated structures and a large number of electrodes for multidirectional control. Herein, a bio-inspired spider-net-coding (BISNC) interface with great flexibility, scalability, and single-electrode output is proposed, through connecting information-coding electrodes into a single triboelectric electrode. Two types of coding designs are investigated, i.e., information coding by large/small electrode width (L/S coding) and information coding with/without electrode at a predefined position (0/1 coding). The BISNC interface shows high scalability with a single electrode for detection and/or control of multiple directions, by detecting different output signal patterns. In addition, it also has excellent reliability and robustness in actual usage scenarios, since recognition of signal patterns is in regardless of absolute amplitude and thereby not affected by sliding speed/force, humidity, etc. Based on the spider-net-coding concept, single-electrode interfaces for multidirectional 3D control, security code systems, and flexible wearable electronics are successfully developed, indicating the great potentials of this technology in diversified applications such as human-machine interaction, virtual/augmented reality, security, robotics, Internet of Things, etc.