A power-generating backpack has been developed by researchers at the
“The suspended-load backpack could help anyone with a need for power on the go, including researchers, soldiers, disaster relief-workers or someone just looking to keep a mobile phone charged during a long trek,” said Larry Rome, the backpack’s inventor and professor of Biology at the University.
During the war in
The suspended-load backpack is based on a rigid frame pack, much like the type familiar to hikers everywhere; however, rather than being rigidly attached to the frame, the sack carrying the load is suspended from the frame by vertically oriented springs. It is the vertical movement of the backpack contents that provides the mechanical energy to drive a small generator mounted on the frame.
Previous efforts to solve dilemma of the over-burdened soldier incorporated devices placed in the heels of boots. According to
“As humans walk, they vault over their extended leg, causing the hip to rise 5-7 centimetres on each step. Since the backpack is connected to the hip, it to must be lifted 5-7 centimetres,”
The amount of power generated depends on how much weight is in the pack and how fast the wearer walks. The Penn researchers tested packs with loads of 40 to 80 pounds and found that the wearer could constantly generate as much as 7.4W while moving at a steady clip. Typically, cell phones or even night vision goggles require less than one Watt to power.
Contrary to what might be expected, wearing the suspended-load backpack does not use up much more metabolic energy than walking while wearing a conventional backpack of the same weight. According to
“Metabolically speaking, we’ve found this to be much cheaper than we anticipated. The energy you exert could be offset by carrying an extra snack, which is nothing compared to weight of extra batteries,”