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A sophisticated nanofoam materials guarantees improved safety and luxury for sports activities gear, with potential purposes in automobile security techniques and wearable medical gadgets. The modern materials overcomes the constraints of conventional nanofoam, offering a versatile and comfy resolution that may face up to a number of impacts. (Artist’s idea dramatizing the “liquid” security cushion.)
New breakthrough in materials design will assist soccer gamers, automobile occupants, and hospital sufferers.
A major breakthrough within the subject of protecting gear has been made with the invention that soccer gamers had been unknowingly buying everlasting mind injury from repeated head impacts all through their skilled careers. This realization triggered an pressing seek for higher head safety options. Amongst these improvements is nanofoam, a fabric discovered inside soccer helmets.
Due to mechanical and aerospace engineering affiliate professor Baoxing Xu on the College of Virginia and his analysis staff, nanofoam simply acquired an enormous improve and protecting sports activities gear might, too. This newly invented design integrates nanofoam with “non-wetting ionized liquid,” a type of water that Xu and his analysis staff now know blends completely with nanofoam to create a liquid cushion. This versatile and responsive materials will give higher safety to athletes and is promising to be used in defending automobile occupants and aiding hospital sufferers utilizing wearable medical gadgets.
The staff’s analysis was just lately printed within the journal Superior Supplies.
A diagram illustrating how a liquid nanofoam cushion responds to an influence. Credit score: Contributed by B. Xu
Upgraded Nanofoam: Developments and Potential
For optimum security, the protecting foam sandwiched between the interior and outer layers of a helmet shouldn’t solely have the ability to take one hit however a number of hits, sport after sport. The fabric must be cushiony sufficient to create a smooth place for a head to land, however resilient sufficient to bounce again and be prepared for the following blow. And the fabric must be resilient however not arduous, as a result of “arduous” hurts heads, too. Having one materials do all of these items is a reasonably tall order.
The staff superior their work beforehand printed within the Proceedings of the Nationwide Academy of Sciences, which began exploring the usage of liquids in nanofoam, to create a fabric that meets the advanced security calls for of high-contact sports activities.
“We came upon that making a liquid nanofoam cushion with ionized water as an alternative of standard water made a major distinction in the way in which the fabric carried out,” Xu mentioned. “Utilizing ionized water within the design is a breakthrough as a result of we uncovered an uncommon liquid-ion coordination community which made it doable to create a extra refined materials.”
Affiliate Professor Baoxing Xu within the UVA Division of Mechanical and Aerospace Engineering. Credit score: Tom Cogill
Enhanced Efficiency and Consolation
The liquid nanofoam cushion permits the within of the helmet to compress and disperse the influence drive, minimizing the drive transmitted to the top and lowering the chance of damage. It additionally regains its authentic form after influence, permitting for a number of hits and guaranteeing the helmet’s continued effectiveness in defending the athlete’s head throughout the sport.
“An added bonus,” Xu continued, “is that the improved materials is extra versatile and way more comfy to put on. The fabric dynamically responds to exterior jolts due to the way in which the ion clusters and networks are fabricated within the materials.”
“The liquid cushion may be designed as lighter, smaller, and safer protecting gadgets,” mentioned affiliate professor Weiyi Lu, a collaborator from civil engineering at Michigan State College. “Additionally, the lowered weight and dimension of the liquid nanofoam liners will revolutionize the design of the arduous shell of future helmets. You might be watching a soccer sport in the future and surprise how the smaller helmets defend the gamers’ heads. It might be due to our new materials.”
Overcoming Conventional Nanofoam Limitations
In conventional nanofoam, the safety mechanism depends on materials properties that react when it will get crunched, or mechanically deformed, similar to “collapse” and “densification.” Collapse is what it appears like, and densification is the extreme deformation of froth on sturdy influence. After the collapse and densification, the standard nanofoam doesn’t get better very nicely due to the everlasting deformation of supplies —making the safety a one-time deal. When in comparison with the liquid nanofoam, these properties are very gradual (just a few milliseconds) and can’t accommodate the “high-force discount requirement,” which suggests it will possibly’t successfully soak up and dissipate high-force blows within the brief time window related to collisions and impacts.
One other draw back of conventional nanofoam is that, when subjected to a number of small impacts that don’t deform the fabric, the froth turns into fully “arduous” and behaves as a inflexible physique that can’t present safety. The rigidness might probably result in accidents and injury to smooth tissues, similar to traumatic mind damage (TBI).
By manipulating the mechanical properties of supplies — integrating nanoporous supplies with “non-wetting liquid” or ionized water — the staff developed a approach to make a fabric that would reply to impacts in just a few microseconds as a result of this mixture permits for superfast liquid transport in a nanoconfined atmosphere. Additionally, upon unloading, i.e., after impacts, resulting from its non-wetting nature, the liquid nanofoam cushion can return to its authentic type as a result of the liquid is ejected out of the pores, thereby withstanding repeated blows. This dynamic conforming and reforming capability additionally cures the issue of the fabric turning into inflexible from micro-impacts.
Prolonged Purposes of Liquid Nanofoam
The identical liquid properties that make this new nanofoam safer for athletic gear additionally supply a possible use somewhere else the place collisions occur, like automobiles, whose security and materials protecting techniques are being reconsidered to embrace the rising period of electrical propulsion and automatic automobiles. It may be used to create protecting cushions that soak up impacts throughout accidents or assist scale back vibrations and noise.
One other objective that may not be as evident is the function liquid nanofoam can play within the hospital setting. The froth can be utilized in wearable medical gadgets like a smartwatch, which screens your coronary heart charge and different important indicators. By incorporating liquid nanofoam know-how, the watch can have a smooth and versatile foam-like materials on its underside and assist enhance the accuracy of the sensors by ensuring proper contact with your skin. It can conform to the shape of your wrist, making it comfortable to wear all day. Additionally, the foam can provide extra protection by acting as a shock absorber. If you accidentally bump your wrist against a hard surface, the foam can help cushion the impact and prevent any harm to the sensors or your skin.
Reference: “Nanoconfined Water-Ion Coordination Network for Flexible Energy Dissipation Device” by Yuan Gao, Mingzhe Li, Chi Zhan, Haozhe Zhang, Mengtian Yin, Weiyi Lu and Baoxing Xu, 6 July 2023, Advanced Materials.
DOI: 10.1002/adma.202303759