Student Article High School Science Journal Author: Brandon Johnson

A New Definition to Power Walking

July 19, 2007

Imagine someone being able to power electric devices without the use of batteries or solar energy as they walk. Scientist from the University of Pennsylvania and a Marine Biological Laboratory located in Massachusetts has created a backpack that allows the user to generate electricity from the energy their legs produce. The electricity is then used to power various electrical devices.

The sciences behind this new invention exist between the wearer and a small compartment in the backpack. As the wearer walks, a cloth pack inside the backpack moves up and down a metal frame, this allows the energy to be transferred to an electrical generator. Inside the generator, are coils of wire within a magnetic field. The coils turn when they walk, leading to the production of electricity. Interestingly, the springs that hold the frame allow the load to slide up and down with the same motion of the hip. In a simple equation, the amount of load carried, in addition to the speed of the walker, equals the amount of electricity produced. 

            Although the modified backpacks are heavier than typical backpacks, they are more comfortable and allow the user to use less energy. Inventor Larry Rome says: “The suspended load backpack is much more comfortable to wear than a normal backpack, because the springs cushion the load and reduce peak forces. So everyone from the military to kids carrying heavy book bags will be benefit from lower forces” (Backpack generates a powerful punch). These backpacks are not limited to, but are best suited for hikers, soldiers, scientists, and emergency workers. As a result of this invention, people will soon be able to watch TV, play video games, listen to music, and do much more as they walk without the use of batteries.

 More importantly, soldiers in war could use the backpack to carry and power required devices weighing an excess of 80 pounds, without the hassle of carrying extra batteries that could add an extra 20+ pounds. Also, this new science based invention could be used in natural disasters. During Hurricane Katrina, phone and radio communication products failed because of power outages. As a result, batteries could not be charged. This new backpack would eliminate future problems during power outages.  Future owners of this product will no longer have to carry heavy and space consuming batteries and related materials.

              In research experiments, people who carried a load of 44 to 84 pounds produced approximately seven watts of energy. Traditional electronics required about one watt each to run effectively. One watt is enough to power most cell phones.  The hip must be raised about five centimeters in order for power to be generated.  Researchers in this experiment also learned that the backpack alters the wearer’s walking movements, resulting in a more balanced and relaxed stride.

            This new backpack will be extremely popular among members of all generations. The ‘device’ may take three or more years to reach the market level, but the possibilities this new creation possesses makes it worth the wait. Unfortunately, the backpack may raise serious security concerns. Someone wearing it may be mistaken as a suicide bomber, or as some other terror threat. This type of problem has prevented many great science inventions from reaching the stores.

 This new backpack will continue to be improved by great scientist and engineers. The science-oriented individuals will improve the backpack by allowing more watts to be produced, installing more input/output outlets, and other additions. The theoretical and concrete concepts of the backpack, may be implemented into similar devices.

 
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