Biomechanical energy harvesting for wearable and mobile devices

Background

Wearable and mobile devices have become an important part of our daily life. Most of these devices are powered by electrochemical batteries, which have limited energy capacity, need periodic replacement or recharging, and lead to environmental concerns. Extracting a small amount of energy from the human body can provide enough power for wearable/mobile devices, and enable a convenient, sustainable, eco-friendly, and self-powered alternative to batteries.

Innovation

• A compact & lightweight energy harvester and novel 2DOF system for energy harvesting backpack are proposed.

• A piezoelectric footwear harvester is designed, modeled and tested with a force amplification frame.

Approach

All the proposed studies are investigated via 3 steps: system design, dynamic modeling, and treadmill tests with human subjects. Different walking speeds and scenarios have been analyzed.

Achievement

Backpack: The novel 2DOF backpack can effectively generating electricity (7.24W @3mph with), while reduce ground reactive force during push-off phase without costing extra metabolism.

Shoe: Experimental results manifest that the footwear harvesters can generate 9 mW/shoe average power outputs at the walking speeds of 3.0 mph (4.8 km/h).