Generating Electricity during Walking with a Lower Limb-Driven Energy Harvester: Targeting a Minimum User Effort

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Energy Harvesting

Background:

• Energy harvesting aims for electricity generation during daily activities with minimal user effort.
• Previous studies overlooked the metabolic cost of carrying energy harvesters.
• No prior harvester exceeded 5W while maintaining comparable or lower user effort than conventional methods.

Purpose of the Study:

• To develop a lower limb-driven energy harvester capable of significant electricity generation.
• To introduce a comprehensive performance metric, the total cost of harvesting (TCOH), including device carrying costs.
• To evaluate the energetic effectiveness of the novel harvester compared to conventional power generation.

Main Methods:

• Development of a lower limb-driven energy harvester utilizing generative braking.
• Implementation of the total cost of harvesting (TCOH) metric for performance evaluation.
• Testing with 10 participants under various walking conditions to assess TCOH and power output.

Main Results:

• The novel harvester generated approximately 9W of electricity.
• The average TCOH for the harvester was 6.1, comparable to conventional methods (6.2).
• At 5.2W generation, the harvester's TCOH (4.0) was lower than conventional methods.

Conclusions:

• The developed lower limb-driven energy harvester is an energetically effective solution.
• This technology offers a viable method for generating electricity during everyday activities.
• The TCOH metric provides a more accurate assessment of energy harvesting efficiency.