Highly Sensitive CNT‐Sponge Triboelectric Vibration Sensor for Machinery Monitoring

Abstract With advances in automation and intelligent manufacturing, where mechanical vibration monitoring has become critical for equipment health assessment, a high‐sensitivity triboelectric vibration sensor using carbon nanotube (CNT)‐modified conductive sponge architecture is proposed. The developed sensor consists of a porous conductive sponge matrix uniformly coated with carbon nanotube solution and a fluorinated ethylene‐propylene (FEP) film. Systematic characterization revealed that the CNT‐functionalized sensor exhibited a remarkable enhancement in output voltage (ΔV = 204% at 80 m⁻¹s² acceleration) compared to original counterparts, demonstrating superior sensitivity (4.47 mV m⁻¹ s²) across an extended acceleration range (5–80 m⁻¹s²). The optimized structural configuration (0.1 mm gap, 0.5 mm sponge thickness) enabled broadband frequency detection from 1 to 500 Hz. In the durability test of up to 216 000 working cycles, its output voltage remains stable, showing no significant attenuation or drift. Moreover, tests conducted on marine equipment such as blowers and air compressors further validate the sensor's precise vibration monitoring capability, as the measured frequency highly matches the actual vibration. This research provides new ideas for mechanical vibration sensing technology and is expected to be widely applied in industries such as manufacturing and shipping, contributing to the intelligent upgrading and sustainable development of various industries.