Gear-Pump-Based Turbine Generator for Human Gait Energy Harvesting in Footwear

This paper presents a novel approach to harvesting biomechanical energy from human gait in footwear. A hydraulic method is proposed, analyzed and optimized. The gait cycle and fluidic system are examined in detail and an optimized gear-pump based turbine is suggested to leverage the high pressure and low flow rates available. A prototype system is developed, manufactured and tested. It is coupled to a custom designed electromagnetic generator. The entire system is filled and submerged in oil. The system consists of two balloons with diameter 4.5 cm and 2.5 cm height, as well as a turbine generator that is 5×5×2.7 cm
³
. By stepping on the generator an 80 kg person can produce 1.17 W peak with a cadence of 1 step/sec, leading to a power density of 8 mW/cm
³
and 291 mJ/step considering all three phases.