Design Engineering

“Floating backpack” focuses on engineering to make your daily commute easier

Devin Jones   

General Materials Energy Floating backpack Office of Naval Research

HoverGlide backpack’s "Suspended-Load Technology" reduces perceived weight carried.

After working with the U.S military on a rucksack capable of generating electricity through motion, biology professor Dr. Lawerence Rome has introduced the HoverGlide: a backpack that reduces it’s weight through a patented frame and series of pulleys.

As a biology professor at the University of Pennsylvania and self-proclaimed expert on muscle function and biomechanics, Rome was approached by the Office of Naval Research (ONR) to figure out a way to reduce the large loads Special Operation Forces have to carry. His solution, is something called Suspended Load Technology (SLT). It’s the technology behind the military-grade Lightning Pack and his consumer grade ergonomic-focused HoverGlide line of products.

“We call it Suspended-Load Technology (SLT). As you walk or run your torso moves up and down with each step. This means you have to decelerate and accelerate the load in you pack ever time your foot hits the ground,” says Rome. “The peak vertical force exerted by the backpack during running is 3X the weight of your backpack—so for 50 lb load—that makes it 150 lbs. Our packs keep the load at a constant height and no long needs to decelerate and accelerate. We reduce this extra accelerative force by 82-86% making it more comfortable and less injurious to carry a load,” he says.

The HoverGlide and it’s patented technology works off of a two-frame system with an elastic cable between them. One frame contains the hipbelt and harness, which attaches to you like a normal backpack. The bag which carries the load is attached to the second frame. The second frame is attached to the first frame by a long elastic coupling.  As you walk and the frame attached to you moves up and down, the elastic cord gets stretched and shortens in such a way that the frame with the bag attached stays at a constant height.


The HoverGlide currently comes in four different iterations aimed at different functions. There’s the Trekker for those going on multi-day hikes, a smaller verison for day hikes, as well as a tactical pack for first responders and a commuter model focusing on city use.

According to Rome, the idea for the Lighting Pack came first, after the ONR asked if there was a way to get rid of the extra 20 lbs soldiers were carrying in batteries, instead generating electricity from their movement. During that initial phone call Rome had the idea of creating a pack that would do the trick, but the question was: how exactly would it work?

“We recognized that the vertical movement of a heavy load in the gravitational field during walking represents an untapped source of mechanical energy and a potential opportunity to generate substantial levels of electricity,” Writes Rome in a paper published in Science Magazine. “If one is carrying weight in a backpack, because it is fixed to the body, it has to go up and down the same vertical distance. A considerable amount of mechanical energy must be transferred (or generated de novo by the muscles) if the load is heavy. In the case of a 36-kg load, 18 J of mechanical energy transfer (or work) accompanies each step (assuming 5 cm displacement), and at two steps this is equivalent to 35 W.”

One of the initial design challenges Rome came across was the conduit for generating energy. Most designs for generating electricity through movement were focused on a shoe, which as Rome points out, despite the “considerable effort that has gone into developing exotic energy-generating technologies for shoe devices, the small magnitude of the mechanical energy source remains a limitation.”

According to the specifications page on the Lighting Packs website, the military-focused rucksack can generate 20-35 watts of power while “hump walking,” and 25-50 watts while “hand pumping.”

Currently, the HoverGlide has met and exceeded it’s Kickstarter goal of CA$97,210 to the tune of CA$ 212,324.


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