CHINA- The new backpack model reduces the impact on the wearer, while generating electricity to power LEDs or other equipment.
Experts at Tsinghua University developed a backpack equipped with shock absorbers that make the wearer feel lighter and can generate electricity, New Scientist reported on Feb. 4. The new study is published in the journal ACS Nano.
The backpack is suspended by sliders, which can be moved up and down thanks to a pair of rubber bands of the pulley system. This system works similarly to the suspension of a car, which reduces the impact of the backpack on the wearer when walking. This reduces the impact force generated by about 21% when items in the backpack bounce.
“When we walk, the body’s center of mass shifts up and down,” said Jia Cheng, an expert at Tsinghua University who was part of the research team. Conventional backpacks will move with the center of mass, but the pulley system of the new backpack model suppresses this movement. Then, the relative displacement between the backpack and the human body runs the nanofriction generator (TENG), turning mechanical energy into electricity.
When users wear a backpack on their shoulders and walk, TENG can turn 14% of the backpack’s movement into electricity, generating about 118 microjoules (μJ). In the study, experts used this electricity to light LEDs, fluorescent lights or electronic clocks.
“This is an exciting study in electronics and a step forward for green electronics,” said Chan Hwang See, an expert at Edinburgh Napier University. He hopes the team will increase TENG’s energy efficiency, making it lighter. The current version weighs up to 3 kg, so it is difficult to use widely.
Cheng agrees with this goal. “The prototype is still a bit heavy, but I think we’re going to reduce the weight and make it more practical in the future, while increasing energy efficiency,” he said. Cheng expects the next version to be only 1 kilogram.
Thu Thao (According to New Scientist)
