Smart Backpack Lightens Load, Generates Power As You Walk
Backpacks are great for carrying your belongings as they distribute the weight of the backpack evenly across the body so that it is supported by the body’s strong back and abs. But that doesn’t mean they couldn’t be better. A backpack that is cluttered or containing bulky items is still heavy, and a long hike with an overcrowded backpack will take its toll the next day.
Researchers in China have found a way to make a smart backpack that feels 20% lighter – and no, you don’t have to take a fifth of the contents out of your backpack before heading out. Instead, it’s about giving the backpack a car-style suspension system.
“Two elastomers, two slide rails, and two pulley blocks are arranged symmetrically on two sides of the frame,” Jia Cheng, associate professor at the Institute of Mechanical Engineering at Tsinghua University in Beijing, told Digital Trends. “One end of an elastomer is attached to the top acrylic plate by two fixed pulleys, while the other is attached to the frame. The load is fixed on the top acrylic plate, and the top acrylic plate can move up and down on the slide rails. “
The weights of the load and the upper acrylic plate are balanced by the elastic force of the two elastomers. As a result of the firm connection between the backpack frame and the body, the frame moves up and down synchronously with the center of mass of the wearer’s body when walking.
Tsinghua University / ACS Nano
“Without the up and down movements of the load while walking, the wearer feels lighter than before,” Cheng said. “… The absolute displacement of the load to the ground is almost zero and there is no vertical fluctuation.”
That’s not all
A backpack that feels lighter would be enough for many researchers. But clearly not for Cheng and team. The prototype backpack can also obtain mechanical energy from human movements and use this to power the on-board electronics. This is done with the help of a triboelectric nanogenerator (TENG).
No, you will likely not be able to turn off main power to your desktop computer if you instead walk on a treadmill while working. However, the researchers have shown that such a setup can power LEDs, an electric clock, and fluorescent tubes. In environments where power is not available, e.g. B. for rescuers in a disaster area, such a backpack can prove to be invaluable.
An article describing the work was recently published in ACS Nano magazine.