Foam that could mop up on auto safety

TU-Editor

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24th July 2018

‘Low tech’ ADAS still has a place with the high tech, Eric Volkman discovered.

In the ever-accelerating field of ADAS, all eyes are on the latest “oh, wow” technology. It’s easy to miss the fact that there are some intriguing developments coming down the road in the more basic components of automobiles – namely, the body and the interior.

That’s because there’s a new(ish) material in town – syntactic foam. This is a type of material in which a plastic is suffused with very small, hollow spheres known as microballoons, which are typically made of glass. The microballoons serve two purposes; they cut down on weight considerably and they make the overall structure much stronger than it would be if constructed of more traditional material.

One of the most significant figures connected with the technology is Dr Nikhil Gupta, an associate professor of mechanical and aerospace engineering at New York University’s Tandon School of Engineering. Gupta points out that such materials represent a major leap forward. “Common foams like sponge comprise a plastic suffused with gas pores,” he points out. “These pores have irregular shapes and sizes. Also, when compressed, these pores get compressed and do not resist an applied force. In comparison, the glass shells of hollow particles are strong and can withstand compressive forces, making these foams very strong.” The combination of light weight and high strength holds great appeal for the automobile industry, which is on an eternal quest for weight advantages. Every manufacturer dreams of building their cars to be lighter, faster and more fuel efficient.

Meanwhile, technological advances have made syntactic foams cost-effective for mass production. On top of that, the 3D printing revolution promises quicker and easier manufacture of highly specialized molded plastic forms. Finally, according to Gupta, these forms can be made in a variety of colors and can be painted too. Ultimately, then, the scope for syntactic foam adaptation is very wide – it not only has the potential to be a go-to solution for car interiors, versions skinned in metals could also be used for other components.

“Aluminium and magnesium matrix syntactic foams have been synthesized and studied for high temperature and dynamic loading conditions that are relevant to engine applications,” says Gupta. “It is expected that these materials will result in significant weight reduction under the hood.”

Those in the auto industry familiar with advances in syntactic foam are, naturally, hopeful about its potential but this comes with a caveat or two. When asked about the future of this material, John O’Donnell, president and CEO of the Washington (DC) Area New Automobile Dealers Association, is guardedly positive. “Assuming cost-effectiveness, any advancement that manufacturers can make that would improve fuel efficiency without sacrificing consumer safety is something we would wholeheartedly support,” he says. Reiterating those concerns, he adds that “for over 100 years, automakers have been developing ways to make cars cleaner, safer, and more fuel-efficient. We support any initiatives that continue that forward progress in a way that gives consumers more choices, without sacrificing safety”.

Although syntactic foam might be new to some in the automobile manufacturing space, its origins stretch back several decades. The Bakelite Company, the US maker of the first artificial plastic, coined the term in the 1950s for an early form of the material it had developed. Since then, it’s found its way into the transport sector, notably in components used in submarines and surface ships. It’s even used in the deckhouse (cabin) of the massive American aircraft carrier USS Zumwalt. Two famous submarines – Artemis, the Bluefin-21 that played a role in the search for the missing Malaysia Airlines flight 370 in 2014, and the Deepsea Challenger piloted by The Terminator director James Cameron to explore the Mariana Trench in the Pacific, both used syntactic foam. The material can be made to be very buoyant, hence its use in marine crafts; its toughness is particularly suitable for deep sea craft that must withstand high levels of pressure.

Outside of seaborne vessels, we find syntactic foams in a very wide range of applications. They make their way into certain components of oil and gas pipelines, and can be found in mission-critical parts of rocket boosters. Closer to Earth they’re also used in the manufacture of sporting equipment. In fact, Adidas started employing the material for its official World Cup game balls over 20 years ago. The company says that its incorporation in the Adidas Tricolore that sailed across the pitches in the 1998 contest “improved the ball’s durability, energy return and responsiveness.”

All this is to say that syntactic foam is a dependable material with a very wide of applications that has proven its durability over time. Now that researchers like Gupta and his team are devoting their efforts to making it more cost-effective and broadening its range of uses, we shouldn’t be surprised to see it forming various parts of our cars in the proximate future.

Gupta, of course, is very optimistic. “The technology of these materials is now developed sufficiently to mass produce parts for automobiles,” he says. “Many applications can be identified where they will provide [the] benefit of light weight and high performance.”