Transparentportation: Concept car gets “all clear”

Rinderknecht’s “eXasis” has a transparent body and floor made of polycarbonate (Makrolon) from Bayer MaterialScience (BMS) AG. The Rinspeed Inc. creation, built by Swiss engineering specialists Esoro, debuted at this year’s Geneva Motor Show — 40 years after Bayer presented the first “all-plastic” car.

“In this ethereal transparency, the true spirit of the eXasis becomes visible. An abstract idea becomes material and visions become tangible. Still, the eXasis doesn’t seem to have quite arrived in our material world,” says Rinderknecht.

And, according to the manufacturer, “Glancing through the transparent floor while the car is moving is a very special kind of thrill.” Unlike the first two cars Rinspeed and Bayer collaborated on — the futuristic-looking Senso and the zaZen sports car — this one is not based on a production vehicle.

eXasis’ insect-like, shiny yellow body with exposed wheels seats two people, one behind the other. The cigar shape is distinguished by what the company describes as a “sexy rear section” with a highly polished Remus exhaust muffler. Tailor-made springs and shocks are vertical in front and horizontal in the rear due to limited space. Pirelli 22-in. P Zero tires surrond forged five-spoke wheels.

To offer an unrestricted view of the compact 2-cylinder, 750-cc Weber engine, which sits above the transmission, an additional gearbox was needed. The car weighs only 1,650 lb. Its transparent shell reveals an aluminum chassis, which looks as if it were made from a solid piece. The Recaro seats are made of twelve transparent ribs. Head restraints and armrests are transparent Technogel, a plasticizerfree polyurethane gel with shape memory. And the wheels, trim, wishbones, fuel tank, and headlamps are glass-fiber-coated aluminum. Even the indicator and dashboard instruments are see-through. Transparent touch panels are coated with electrically conductive Baytron.

The 150-hp Weber engine runs on bioethanol, which has the sam chemical formula as traditional ethanol (C2H5OH). Ethanol is only called bioethanol if it comes from vegetable raw material like wood, beets, corn, and grass. These renewable energy sources are known as biomass.

This is the eighth time Esoro has served as general contractor for an entire vehicle. The company handled project management, new technologies, engineering, design, and manufacturing. From initial concept, it took Esoro’s team only six months to build the prototype.

The Swiss Federal Office of Energy is involved because of the concept’s energy-efficient lightweight construction and because it’s powered by renewable energy. Reducing a vehicle’s body weight gives rise to lighter components and smaller, lighter engines. Though eXasis will never be mass produced, components and assemblies based on its technology could help cut fuel consumption.