MindTribe has an orb in the office that we need to stop watching. The orb glows red when the NASDAQ drops, glows green when it rises, and pulses when the index’s movement exceeds 4%. Lately, its perpetually pulsing red light has been making me feel as if a hooker moved in to the next row of cubicles. Ironically, the orb can’t be reconfigured to monitor something more optimistic than tech stocks because—in a true sign of the times—the Web site that supports it is now defunct.

The Orb Glows Red When the Market Is Down – Lately, We’ve Needed a
Distraction from Its Bad News (photo credit: MindTribe)

In an effort to watch something other than the markets, I asked our MEs and friends for some material innovations that are fun to think about as a diversion. The dream team came up with five materials that are fascinating enough to distract you momentarily from your 401K.

Auxetics

Auxetics thicken when stretched. Pull on most materials and they become longer in the direction pulled and thinner opposite to the pulling force. Think of stretching a rubber band to shoot it from your finger and how it narrows in diameter. Unlike rubber bands, if you stretch auxetics in one direction, they expand in the perpendicular direction.  (See the Auxetic Materials Network)

Auxetics are both naturally occurring (e.g., cow teats) and man-made (certain polymers). Their unique property is a result of their underlying formation. Auxetics have a hexagonal microstructure that works like a hinge. When pulled, the hinge-like structure pushes out the substance in the perpendicular direction.

Hexagonally-Shaped Auxetic Structure Before and After Being Stretched
(Image credit: MindTribe)

One useful implication of this property is what happens when the material is hit. With a conventional substance, e.g., standard foam, the material compresses at the point of impact and the force is dispersed by spreading perpendicular to the impact. That is, the material pushes out away from the point where is it hit, making the non-auxetic material thin at the point of impact and vulnerable to breakage. With auxetics, the material pushes in toward the point of impact, making the material more resistant to breakage.

Because of this impact resistance—not to mention the potential funding opportunities from Homeland Security—literature about auxetics focuses on how they might be used to make military gear like bullet-proof helmets.  Another potential application of auxetics is as a substitute for conventional polymers in arterial replacement. Artificial arteries fabricated from normal plastics narrow in diameter when stretched by a body movement. If the artificial arteries could be made of auxetics, they could elude inadvertently cutting off the blood supply.

Closer to the typical MindTribe project, an immediate commercial application seems to be how we can use these materials to mount electronics like displays to resist breakage during a drop. Or alternatively, they might serve as an attachment fixture. If we compressed auxetic material into an opening it would be hard to pull out, working like a malleable mechanism similar in function to a molly bolt.

Tegris^TM

To address the need for affordable materials that are both lightweight and strong, Milliken & Company has produced a composite material branded “Tegris,” which it markets as an alternative to carbon fiber composite. Tegris has about 70% of the strength of carbon fiber composite, and it is only about 10% of the cost.

Auto racing has a way of driving material innovation. Carbon fiber might be fine for Formula 1 budgets, but what about racing’s poorer cousins? NASCAR adopted Tegris for use in its splitters. Unlike carbon fiber, it doesn’t splinter when it breaks, which prevents having sharp pieces of splitter lying on the track after the typical NASCAR pile up. (Maybe it’s something even Adrian Sutil would lobby for after that unfortunate tire puncture at the F-1 Japanese Grand Prix.)

Tegris-Based NASCAR Splitter Being Examined by a Race Official
(photo courtesy of Milliken & Company)

Tegris-Based Splitter Survives a Crash Intact, Even When the Impact Breaks
the Steel Supports
(photo courtesy of Milliken & Company)

Tegris is composed of polypropylene threads fused together in successive layers. The patented process starts with a polypropylene structure co-extruded as a film, which is then slit into tapes and highly drawn to create a stiff, strong core. The tape yarn is woven into a fabric, and successive fabric layers are pressed together to create a single piece using thermoforming. The outside layers fuse together, playing the same role that the epoxy or resin plays in a carbon-fiber composite, while the core provides the structural strength. Layers are stacked and pressed together at very high pressure, then cut using water jets (like the one MindTribe helped develop for Flow International). The NASCAR splitter uses 100 layers of the fabric.

According to Milliken, the composite provides two to fifteen times the impact resistance of a typical thermoplastic. While Tegris is not as light or as stiff as carbon fiber composite, it is fully recyclable, unlike carbon fiber. The material returns to standard polypro upon melting during recycling. Also, by avoiding the use of glass for stiffening, Tegris won’t wear out molds the way fiberglass does.

The applications beyond motorsports currently include other less motorized vehicles like kayaks and canoes. With its strength and weather resistant properties, one could also imagine outdoor furniture formed from the material. Tegris-based patio seating would be a good project for Milliken to engage some design team like Mike and Maaike, a team with a fresh take on tired categories, to explore.

Catalyst-Infused Aerogels

With our energy and environmental outlook almost as bleak as our near-term economy, people seek promising ways to improve the situation. The process of catalysis is being heralded as an environmental and industrial godsend for the future.  Catalysis is a process that speeds the rate of a chemical reaction by means of a chemical substance known as a “catalyst.” The catalyst is not consumed in the reaction; it expedites it. Through its chemical assistance, catalysis reduces the amount of the other substances consumed in the reaction, as well as the waste byproducts. Typically, catalysts also allow the reaction to occur at lower temperatures, thereby conserving energy.

Precious metals, particularly platinum metals, are often catalysts for many common applications like catalytic converters in cars. But precious metals are expensive. (That’s why thefts of catalytic converters are rampant lately.)

Now researchers at Stanford University have been experimenting with ways to reduce the quantity of precious metals required in application to achieve the catalytic reactions. They have devised composites using carbon aerogels, which are highly porous (the surface area of carbon aerogels ranges between 400-1000 m²/g), in conjunction with a catalyst like platinum. The process involves using Atomic Layer Deposition (ALD) to apply a “coating” of platinum to the surface area of the aerogel particles. The resulting material has a high amount of platinum surface area, but reduces the overall amount of platinum required since the volume is not solid platinum. According to the Stanford researchers, even with platinum exceeding $2,000 an ounce, the amount of platinum required for their aerogel “chip” would still cost less than a penny. In their tests, the aerogel infused with platinum was able to catalyze 100% of carbon monoxide into carbon dioxide. (See Nanotechnology research could take the cost out of catalysis)

Stanford Researchers Are Infusing Aerogel with Catalysts like Platinum
(photo courtesy of Stanford Engineering)

Beyond the standard automotive catalytic converter, catalyst-infused carbon aerogels extend really nicely to hydrogen fuel cells. According to the Stanford team, in such applications, carbon aerogels would work well not only because they are good catalysts. Carbon aerogels conduct electricity, which could help reduce loss of electrons transitioning out of the fuel cell and into the device it is charging. American Aerogel in Rochester, New York, a company that provides aerogel primarily for its insulation properties today, has seen an increase in inquiries regarding fuel cell applications.

Magneto-Rheological Fluids

Some of the inspiration for this blog came from an ultra-cool product designer that I met while I was in Singapore for the Formula 1 race. Teo Dabov not only knows materials; he looks somewhat like Fernando Alonso, the Renault driver who unexpectedly won that race. Over startlingly bad coffee in the hotel restaurant one morning, Teo and I got to discussing materials, and he turned me on to magneto-rheological fluids.

Product Designer Teo Dabov Knows about Materials and Looks Like
Two-Time Formula-1 Champion Fernando Alonso
(photo courtesy of Phil Hobson)

Magneto-rheological (MR) fluids are the result of micrometer-sized magnetic particles suspended in a carrier fluid like oil. They are sometimes called “smart fluids” because one can control the viscosity by applying different intensities of a magnetic field.  When a field is being applied, the MR fluid’s consistency can be instantaneously changed from a free-flowing liquid to a visco-elastic solid. The yield strength of the substance is completely controllable by the intensity of the magnetic field.

MR fluids are reminiscent of ferromagnetic fluids in some ways, but ferrofluids primarily consist of nanoparticles that remain suspended in their fluid. This leads to different application for the two types of fluids. Ferrofluids are typically used for their friction-reducing qualities, for example, liquid seals that use a magnetic field to hold them in place. (See more.)

The applications of MR fluids are fascinating to ponder. The ability to control the resistant force with an electromagnet lends itself to control-based applications. The uses so far are for things like shock absorbers that use MR fluid, with the magnetic field dynamically controlling the amount of damping the shock provides. MR fluid is also used in vehicles to control the rotational motion of a clutch, and in human prosthetic legs to decrease the shock to the leg when its wearer jumps. (MindTribe would be a “shoe” in for a project to develop something like that!) These are all fairly large-size products, making me wonder about the applications in something smaller, say hand-held devices. MR fluids might enable some pretty novel interface options for control features like physical button layouts that change dynamically based on context.

Transparent Aluminum

The name of this material really got me excited when Alan Laursen, a mechanical engineer at MindTribe, suggested it for this blog. Beyond the Star Trek movie’s water tanks for humpback whales, “transparent aluminum” brought up visions of invisible cooking pots and see-through foil for leftovers. I just don’t get as excited about the actual applications, which appear currently to be exclusively military. Still, most defense technology can be adapted for less violent means—although, that said, some of the leftovers at MindTribe turn out to be just as deadly.

Containers Hide Nasty Leftovers of Mass Destruction—Too Bad Transparent
Aluminum Isn’t Cost-Effective for See-Through Lids or Other Consumer Applications

The process of making aluminum transparent apparently is comparable to the process that makes glass transparent. According to one Web site that describes that process, glass becomes transparent by messing with molecular alignment via temperature changes: “The process of heating and cooling the glass ingredients transforms them into a molecular stew and solidifies them in that same liquidlike [sic] state with all of the molecules unaligned with one another, enabling light to pass through the hardened glass.”

To create transparent aluminum, Raytheon starts with a powder comprised of aluminum, oxygen and nitrogen. This powder is molded and baked the way a ceramic is baked. The powder liquefies and then cools into a solid, creating a rigid crystalline structure. The resulting aluminum alloy molecules are arranged as if still in liquid form. Polishing strengthens the material and makes it clear.

Apparently, the heating and handling involved makes the process for creating transparent aluminum prohibitively expensive outside the surreal budgets of defense contracting. The substance has been layered onto bullet-proof glass in vehicle-window size prototypes. The good news for soldiers is that transparent aluminum-coated glass weighs half as much and is half as thick as conventional bullet-proof glass, but has the ability to stop anti-aircraft fire.

Too bad we can’t use it as a coating on touch screens any time soon, not to mention as a way to transport whales or monitor refrigerator contents.

Looking into the Orb

At the next cocktail party—the last F-1 race of the season at the Hobsons next Sunday?—hopefully these materials will make for better discussion than the latest statement from Bernanke or Paulsen. Yet, despite the economic downturn, business at MindTribe still has a healthy exuberance about it. The flashing orb does keep us mindful of our blessings. Some of our clients may be “too big to fail” (and we know what that means after Lehman). More likely, in the case of our large corporate clients, the projects are too strategic to cancel. For our startup clients, it seems like innovation is the best investment compared to the alternatives. Most entrepreneurs seem to trust their own instincts and skills by investing in their own ideas.

As my colleague Adam pointed out, if worst comes to worst, we can move the orb to the window at MindTribe, the red light blinking, and develop a whole different “consulting” business.  Maybe that would support our plans for adding a San Francisco office given the recent legal movements there.

Acknowledgements
Subject matter: Teo Dabov, Geoff Nichols, Troy Edwards, and Alan Laursen
Photos and images:  Jerry Ryle, Milliken & Company, Phil Hobson, David Orenstein and Jeffrey King (Stanford engineering)
Kibitzers: Tom Hsiu, Adam Rothschild, and Tim Prachar for pointing out those who were once called “prostitutes” prefer to be called “sex workers.”

Tags: aerogel, auxetic, auxetics, catalysis, catalyst-based aerogel, catalyst-infused aerogel, ferrofluids, ferromagnetic fluids, Jeffery King, magneto-rheological fluids, magnetorheological, material, MR fluids, nanotechnology, NASCAR splitter, NASDAQ decline, orb, platinum catalyst, polypropylene, Raytheon aluminum, Singapore grand prix, stanford engineering, Tegris, Teo Dabov, transparent aluminum

This entry was posted on Wednesday, October 29th, 2008 at 10:40 am and is filed under MindTribe Tech. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.