OCT 25, 2019 10:00 AM PDT

Fridge without Liquid Coolant: How a "Twisted" Idea can Revolutionize Refrigeration Technology

(Pixabay)

In the middle of the night, the low-pitched humming sound from the fridge compressor is likely the most common noise in every household. The fridge's cooling system compresses and circulates the refrigerant vapor, removing heat from inside the refrigerator. 

But this traditional cooling technology is facing a challenger. In a study reported in the journal Science, a team of researchers at the University of Texas at Dallas (UT Dallas) has come up with a brand new refrigeration method that relies on twisted and coiled elastic fibers.

Although most of the current fridges and air conditioners no longer use Ozone depleting refrigerants such as chlorofluorocarbons (CFCs), but the coolants inside them can create a strong greenhouse effect and pose a health hazard if they leak. Moreover, traditional compression-based systems already reach their maximum cooling efficiency, which is about 60%. 

According to the UT Dallas team and their collaborators in the U.S. and China, the innovative solid-state cooling system uses no liquid refrigerants but twisted fibers made out of elastic materials, such as natural rubber, nickel-titanium wires, and polyethylene fishing line. When the coiled fibers become untwisted and stretched, their surface temperature drops, creating a cooling effect due to the change in entropy of the materials. This so-called  "twistocaloric" process can produce a theoretical cooling efficiency of up to 84%.

In an email interview, LabRoots reached out to Dr. Ray Baughman, a Chemistry Professor and the Robert A. Welch Distinguished Chair in Chemistry at UT Dallas, who is also the corresponding author behind the paper. He talked about what inspired them to look into solid-state cooling of twisted fibers.

"Our discovery of twistocaloric cooling was accidental. We had previously discovered that ordinary polymer fibers provide powerful artificial muscles that can be thermally driven," Baughman referred to one of their publications back 2014 which described artificial muscles made with fishing line and sewing thread.

Cheap polymers twist into muscles with superhuman strength (Chemistry World)

In the current study, the chemistry researchers successfully built a prototype fridge that's based on nickel-titanium fiber. It can cool flowing water by 7.7°C in a single cycle. But they won't just stop there. "We have already made improved prototypes that will be described in future publications, and our work on making improved coolers is continuing," said Baughman. 

"Additionally, while our original work used fibers that are commercially available, we are presently optimizing twistocaloric properties by using specially prepared yarns and fibers," he added.

Material fatigue, the deterioration and weakening of structure, can happen to a material after it has performed repeated, cyclic work. "Material fatigue is a problem for previously investigated mechanocaloric materials, considering the enormous number of cycles needed for the over ten year lifetime for conventional refrigerators," said Baughman. "We have not yet encountered the fatigue problem since we have at present investigated only a few thousand cycles. However, we will thoroughly investigate this issue in future work, and correspondingly optimizes our selection of twistocaloric yarns and fibers."

In a press release, Dr. Baughman also commented on the prospective development and potential commercialization of their solid state fridge idea.

“Many challenges and opportunities exist on the path from these initial discoveries to (the) commercialization of twist fridges for diverse large- and small-scale applications,” he said. “Among the challenges are the need to demonstrate refined devices and materials that provide application-targeted cycle lifetimes and efficiencies by recovering part of the inputted mechanical energy. The opportunities include using performance-optimized twistocaloric materials, rather than the few presently studied commercially available candidates.”

Source: Ars Technica

About the Author
  • Graduated with a bachelor degree in Pharmaceutical Science and a master degree in neuropharmacology, Daniel is a radiopharmaceutical and radiobiology expert based in Ottawa, Canada. With years of experience in biomedical R&D, Daniel is very into writing. He is constantly fascinated by what's happening in the world of science. He hopes to capture the public's interest and promote scientific literacy with his trending news articles. The recurring topics in his Chemistry & Physics trending news section include alternative energy, material science, theoretical physics, medical imaging, and green chemistry.
You May Also Like
JAN 21, 2020
Cell & Molecular Biology
JAN 21, 2020
Light Therapy Developed for Treating Carbon Monoxide Poisoning
According to the Centers for Disease Control and Prevention, everyone is at risk from carbon monoxide (CO) poisoning....
JAN 21, 2020
Chemistry & Physics
JAN 21, 2020
Is the Milky Way Too "Gassy"?
Astrophysicists have long thought that our home galaxy the Milky Way has been constantly losing mass due to the escape of hydrogen gas. However, by observi...
JAN 21, 2020
Chemistry & Physics
JAN 21, 2020
Electrifying Breakthrough: New Tech Adds 200 Miles to EVs with only 10-Min Charging
One of the most noticeable drawbacks of electric vehicles (EVs) is their long charging time. That's why the U.S. Department of Energy has set a goal to...
JAN 21, 2020
Space & Astronomy
JAN 21, 2020
Say Hello to the Largest Star Ever Discovered
There are so many stars in the modern universe that we couldn’t ever hope to count them all. Many are so distant from us that we can’t even see...
JAN 21, 2020
Chemistry & Physics
JAN 21, 2020
X17 - The Newest Exotic Particle May Hints a 5th Force Outside the Standard Model
About four years ago, a team of Hungarian physicists at the Institute for Nuclear Research noticed something strange in their experiments with beryllium-8,...
JAN 21, 2020
Space & Astronomy
JAN 21, 2020
NASA's Parker Solar Probe Reveals Telling Clues About Our Sun
NASA’s Parker Solar Probe is currently the closest spacecraft to the Sun today. Being this close gives the spacecraft an unprecedented opportunity to...
Loading Comments...