Adaptive underwater biomechanical energy harvesting belt

Human underwater activities, such as scientific exploration, industrial development, military operations, emergency rescue, and underwater sports, are increasingly prevalent and critical. While wearable devices enhance the convenience and safety of these activities, ensuring a stable and sustainable power supply remains a critical challenge. This paper proposes an adaptive underwater biomechanical energy harvesting belt (AU-BEHB) to address this issue. To accommodate complex underwater human motions, the system employs a dual-adaptive mechanism: a self-regulating excitation angle to align the excitation direction with the driving direction, and a flexible adaptive excitation path to efficiently transmit irregular human motion excitation. This design optimizes energy transfer efficiency while minimizing movement constraints for divers. Combined with a unidirectional frequency-up conversion transmission mechanism, the system improves output power. A multi-level waterproof structural design ensures reliable sealing in underwater environments. Experimental results demonstrate that under a traction excitation of 2 Hz and 300 mm, the two biomechanical energy harvesting units of the AU-BEHB achieve peak voltages of 14.85 V and 18.55 V, with average output powers of 2.09 W and 2.29 W, respectively. Underwater wearable experiments demonstrate that AU-BEHB effectively adapts to different users and motion postures. A single unit is capable of lighting up an LED module with a total power consumption of 3 W. Moreover, AU-BEHB shows potential for underwater self-powered emergency rescue and thermal insulation of critical body parts. The proposed design enhances both wearability comfort and output power, presenting a potential solution for powering underwater wearable electronic devices.