Anti-vaxxers aside, the main reason children don't receive life-saving vaccines is a logistics problem. In remote parts of the world without reliable electricity, it's hard to keep vials at the exact temperature needed for a dose to work. Along with broken vials and other problems, as much as half of all vaccines are wasted in some countries.
A simple new design—inspired by a forgotten invention from 1929 called the IcyBall—maintains a stable temperature and is small enough to slip inside a backpack, so it can easily be carried to rural villages.
Right now, the ice or cold packs that are sometimes used with vaccines can freeze the product so it's no longer potent. Some off-grid refrigerators can be expensive to run or easy to break and can't necessarily help with vaccines en route for delivery.
The Isobar can be charged through electricity, and then keeps the vaccine at a steady cool temperature for up to six days in an insulated backpack. If a delivery takes more time and there's no electricity available, they can recharge the unit using propane.
"The small propane charge means that you can recharge the six-day cycle from anywhere in the world," says Will Broadway, the 22-year-old designer of the device, who first created it as a master's student at Loughborough University.
"This level of flexibility and cooling duration allows the vaccine cold chain to become less volatile," he says. "If your car breaks down in the middle of nowhere, you might find you could lose all of the vaccine, which is equivalent to $3,500 in a 1.6 liter container. This is a huge potential loss of life and money."
Broadway stumbled onto the older invention that inspired him after struggling to find a lightweight but powerful method of cooling. "I couldn't find anything that packed a strong enough punch for the weight," he says. "Electricity requires huge batteries and only lasts a short period of time. Ice and cold packs are inconvenient and don’t work effectively for stable temperature control, and propane fridges regularly fail due to mechanical error and occupy large amounts of space that is just not portable."
The Crosley IcyBall, which was briefly manufactured in the early 20th century, uses heat instead of electricity to evaporate a refrigerant. The technique—originally invented by Einstein—uses heat to pull ammonia from one chamber to another. When a valve opens, the ammonia evaporates back into the original chamber, creating a strong cooling effect.
By tweaking the design, Broadway made a unit small enough to fit in a backpack and made it possible to recharge using either electricity (which powers an internal heating element) or propane.
Because of the tiny size, it also has advantages over traditional refrigeration in storage units. It's less likely to break down, for example.
The same design could also be used to make different types of medical deliveries, like transporting blood or organs. He's also interested in using the unit with drones, for faster delivery without the risk of human error.
The design is currently a prototype, but Broadway is currently building a team to develop it further and begin pilot testing. The Isobar won the U.K. James Dyson award, and is up for the global version of the award now.
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