Power Hiking Backpack

Researchers have developed a backpack that will share the load.

This short article describes an innovative new technology that could assist athletes, explorers and disaster rescuers. The resource is best suited to Year 8 and 10 Physics students learning about energy transfer, energy efficiency or forces. Contextual problem-solving questions are included.

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Close-up of the prototype backpack

Hikers and schoolkids take heart: researchers have developed a prototype backpack that not only makes loads feel about 20% lighter, but also harvests energy from human movements to power small electronics.

As reported in ACS Nano, the new bag could be especially useful for athletes, explorers and disaster rescuers who work in remote areas without electricity, the researchers say.

While they’re brilliant for hands-free load carrying, heavy backpacks can cause walkers or runners back and neck pain. Wilderness walkers (or anyone lacking access to a power source) would find useful a bag that harvests the mechanical energy of walking to small electronic devices.

Earlier energy-harvesting backpacks had relatively low power outputs and didn’t offer load lightening or shock absorption. The research team wanted to design a prototype that overcame these limitations.

The new backpack has two built-in elastomers that stretch and shrink to save effort, absorb shock and keep the bag steady when it’s in use; this yields about a 20% reduced force on the wearer. Movement between the backpack’s frame and its load during walking drives a triboelectric nanogenerator (TENG) to convert mechanical energy into electricity, with 14% efficiency.

The researchers showed that the bag could power LEDs, an electric watch and fluorescent tubes. Once its energy-conversion efficiency is improved, the backpack has promise as a power source for small-scale wearable and portable electronics, such as GPSs and health-care sensors, the researchers say.