2007 Toyota 1/X Concept (© Bruce Whitaker)Click to enlarge picture

Toyota’s 1/x hybrid concept, whose bioplastic exterior contains seaweed, has the same interior space as a Prius, but weighs only 926 pounds — about one-third the weight of a Prius — and aims to double its fuel efficiency.

More than a century ago, Henry Ford made a pragmatic — yet arguably visionary — decision by ditching car body panels made of wood for ones made out of sheet metal. The move increased the speed of automobile construction exponentially, and eventually led to the mass-produced car. However, metal wasn’t the only material in Ford’s arsenal of experimentation.

Ford was actually dabbling with more exotic, less factory-friendly construction materials, such as a soy-based plastic exterior that could survive the mighty swing of an ax blade. He ultimately abandoned such plant-based materials because they were too expensive.

But as a new generation of carmakers and materials researchers attempts to wring more efficiency from (and lessen the environmental impact of) the modern motor vehicle, less conventional building materials are gaining new attention.

From design-oriented projects made of bamboo and glass to Toyota’s 1/x concept, whose bioplastic exterior contains seaweed, decades of research into novel materials seem on the verge of paying off. The question is, when will these starch-infused, shape-changing marvels hit the road, and will they be cheap enough for mere mortals to afford, or will they be another novelty for the billionaire whose Lamborghini has lost its luster?

Here are some of the more promising materials automakers are experimenting with:

Corn, Seaweed & Soybeans: Bioplastics
Plastic doesn’t grow on trees — not yet, at least. Most of it, which is used in everything from water bottles to SUV dashboards, is petroleum-based. For automakers hoping to reduce their carbon footprint — whether to boost their environmental image, or to head off  regulations that would penalize carbon emissions, or a combination of both — the benefits of plant-based plastics are obvious.

For example, the production of bioplastic films derived from cornstarch churns out fewer emissions than the production of those made out of petrochemicals. Plus, they are already in relatively widespread use as eco-friendly industrial packaging, which can even be designed to safely break down in landfills. In April, Frito-Lay unveiled a new Sun Chips bag that’s one-third bioplastic, and the company hopes to have a fully compostable bag by Earth Day 2010.

Challenges: But what’s an advantage for an eco-minded chipmaker is a challenge for automakers. How do you achieve the strength and durability of petroleum-based plastics while preventing the material from biodegrading during the vehicle’s life span? “With enough water and heat, this plastic can break back down into compost,” says Steve Davies, director of communications and public affairs for NatureWorks, which is working with Ford and Toyota to incorporate bioplastics into new vehicles, and whose corn-based Ingeo bioplastic is part of the new Sun Chips bag.

“You have to use special coatings to turn that tendency off, so it won’t hydrolyze back into lactic acid, or basically CO2 and water,” says Davies.  For now, the relative vulnerability of bioplastics to the elements makes it a better fit inside the car, particularly in shaded areas such as the trunk. The Toyota Prius features bioplastic floor mats, and when Mazda unveiled its Premacy hydrogen model in 2007, its seat covers and instrument panel incorporated bioplastic.

Outlook: Carmakers are planning to dramatically increase the use of plant-based plastics. Mazda will begin incorporating a nonfood-based bioplastic (derived from the inedible parts of a to-be-announced crop) in some vehicles by 2013, and Toyota wants to replace 20 percent of its automobile plastics with bioplastics by 2015. Beyond the obvious environmental benefits, such as a seven- or eight-fold drop in CO2 emissions per pound of bioplastic fabric produced (compared to nylon, for example), Mazda believes that the lighter-weight materials could lead to increased fuel efficiency, and potentially better performance.

So when will carmakers be able to use bioplastics for exterior body panels or other substantial components? That depends on how quickly companies like NatureWorks will be able to boost their lightfastness and moisture resistance, and whether (or when) oil climbs back to more than $100 a barrel. When fuel goes up, the price of petroleum-based plastics rises with it, and bioplastics become even more attractive, from a financial standpoint.

What's the oddest material you've ever seen used to create an automobile?

Although the exact time frame is unclear, it seems inevitable that automobiles will be increasingly culled from food crops, preferably from corn husks or other agricultural waste. The process will begin from the inside out, starting with interior trim in the next handful of years, and gradually extending outward. It’s also clear that bioplastics won’t be found exclusively in eco-friendly or luxury vehicles — they’ll be as ubiquitous, and as unassuming, as the plastic already used.

Learn more about bioplastics on Bing