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Wearable Energy harvester offers clean and continuous power for wearable sensors or devices, which can play an important role in the health monitoring, motion track and so on. In this study, we investigated a small electromagnetic resonance wearable kinetic energy harvester. A permanent magnet (PM) which was tied with two springs is forming a 3-degree-of-freedom (3-DoF) vibrator and is put in a box. Ferrofluid was adopted which is adsorbed at the pole of PM and makes the PM away from the surface of the box which decreased the friction significantly. Coils are placed on the outside surface and the electric energy is generated when the PM is vibration. It can be used to harvest kinetic energy of human and offer continuous power. The effect of ferrofluid was simulated and analyzed which indicated that the ferrofluid can keep the PM contactless even under 10 times gravity acceleration. A prototype was developed and tested under different loading conditions. Resistance load experiments results indicated that the proposed harvester can generate 0.75mW average power when walking and 1.4mW when running. An energy storage circuit which can transfer the generated alternating power to 5V direct current was developed to store the electrical power into capacitor. Energy storage experiments results indicated that the average storage power when walking and running are 20.8µW and 35.2µW, respectively. The developed harvester can be placed on the shoe and used to offer continuous

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