A German pneumatics firm called Festo is pulling the piston out of the industrial age. Next up: Reinvent shock absorbers, scooters, and aircraft design, then build an inflatable castle in the sky.
By Christopher Dickey
It pleased the Greeks, as well as other nations, to call wind, breath, pneuma, that which they vaguely understood to be respiration, life, soul. Thus in antiquity soul and wind were in a sense the same thing; and if we were to say that man is a pneumatic machine, we would only be translating the Greeks. - Voltaire, "L'Esprit," in Dictionnaire Philosophique
One by one, Axel Thallemer set the machines in motion. The bread-and-butter machines, as he called them, little demonstration models of pneumatic screw sorters, furniture stress testers, robotic assembly-line grippers, all running on air. Ssshhh-plok! Rrrrrrrr-pip! Pneumatic doors opened and closed, steel claws placed chips on boards, air jets blew bolts off spiral conveyors, and the great hall resonated with sounds from a Walter Mitty daydream. Pocketa-pocketa-queep-pocketa-pocketa: a percussive hissing, plunking, shushing symphony of pneumatic performances so mesmerizing that, at first, I didn't hear the building begin to sigh.
"Listen," said Thallemer, chief of corporate design at Festo AG & Co., the privately held German power tool and pneumatics firm. "Do you hear?" The warehouse-museum where we stood was itself a pneumatic wonder, its walls and roof and Y-shaped cyber-Gothic flying buttresses not only inflated but held in dynamic tension by artificial muscles. Three computers read the ambient wind speed and temperature, flexing the pneumatic sinews as needed to keep the walls taut and erect, bleeding air from the roof when it grew warm and began to expand. This "Airtecture" has withstood sustained gale-force winds roaring through the Swabian hills of southwestern Germany. But today was calm. "The sun has come out," said Thallemer. The panels high above our heads exhaled languorously, like a thing alive. Thallemer sighed, too. "Most of my time is not spent on the fun stuff," he said.
By "the fun stuff," Thallemer meant the astonishing creations coming out of Festo's design department - a vehicle called the Citycyc, the six-legged AirBug, the Airtecture buildings - inventions that could revolutionize the way we inhabit urban streets and other hostile environments. In partnership with subcontractors such as Swiss inventor Andreas Reinhard, who runs a small company called Prospective Concepts, Festo has found new ways to harness the power of air. It is opening up possibilities for pneumatic technology comparable to the revolution that occurred in electronics when transistors replaced vacuum tubes. Combining air-filled "membranes" with "fluidic muscles," Festo is producing prototypes and working models of airships and inflatable buildings, as well as pneumatic runabouts and kite-propelled skateboards.
Jules Verne would have understood; so would Edgar Rice Burroughs and E. M. Forster. In their pre-modernist world, pneumatics epitomized the promise of science. What the atom was to the imagination of the mid-20th century, air was to the late 19th. Verne wrote of pneumatic-magnetic trains conveying commuters from one corner of Paris to another. Burroughs transported men in pressurized tubes among the cities of Barsoom. Forster used air technology for his sci-fi nightmare of life inside an omnipresent Machine. But the 21st-century visions that Thallemer is promoting aren't fiction. This technology works. The only question is how it will end up being used.
By and large, Festo is not what most folks would think of as a fun corporation, if, indeed, they've even heard of it. Wholly owned by two aging brothers, Kurt and Wilfried Stoll, it was founded in 1925 by their father, Gottlieb, for the purpose of producing electric drills and saws. In the 1950s, it began developing pneumatic technologies for assembly-line equipment, and over the next few decades grew into a vast multinational enterprise with factories in Brazil, Bulgaria, Hungary, India, Korea, Mexico, Ukraine, and the US; 250 branch offices worldwide; more than 10,000 employees; and annual sales of about $1.2 billion. According to analysts at Frost & Sullivan, which monitors the industry, the US and European markets for pneumatic equipment amount to $6.3 billion, and Festo gets about 13 percent of that action. Most of its business is in valves and robotic components called pneumatic actuators, in which compressed air drives finely machined rods through finely machined tubes to grip, push, plunge, extrude. Pfffttt.
Festo is already marketing its fluidic muscle as a lighter, faster, stronger, cheaper, and more versatile pneumatic actuator. A team lead by Festo engineer Bernd Lorenz developed the first models, which went into production in 1999, using membranes of high-tensile-strength fibers (PBO, M5, Kevlar, et cetera) woven in precise computer-calculated patterns. But the company is so close-mouthed that, two years later, Frost & Sullivan research manager Mik Sabiers doesn't know what portion of Festo's sales the muscles represent. Thallemer says he doesn't have those numbers either, and won't be getting them.
The flaccid fluidic muscle doesn't look like much - it's a hose with bits of metal at each end - but it converts a very simple idea into a practical industrial component. The dynamic is the same as in Chinese handcuffs, which grow narrower and tighter as you try to pull your fingers out from the woven tubing, but become looser and shorter when you push your fingers together. If you made that toy airtight and blew into it, it would grow wider and shorter. This is what happens when air or fluid is pumped into one of Festo's muscles. It does not balloon in the middle or at one end, as a regular hose would; it grows uniformly wider and shorter - and it pulls.
This power to bunch as biceps do, but with industrial strength and velocity, is what has caused such excitement in Lorenz's membrane division and on Thallemer's corporate design team. The natural world, Thallemer points out, doesn't have a single muscle pushing: The leap of a spider, the flapping of a bird's wing, a boxer's jab, or the blink of an eye - all are achieved by muscles pulling, sometimes directly and sometimes levering with tendons and joints. "Only an engineer does pushing with a piston and rod," he says.
The fluidic muscles are the ultimate expression (to date) of Festo's membrane technologies. They are what keep Thallemer's hall-of-sighs standing among the dreary post-Bauhaus office blocks of the company's headquarters. "Without the muscles, it would immediately collapse," says Thallemer. "They are the key to everything we're doing."
Festo uses similar polymer membranes to create three-dimensional textile structures in which the air-filled spaces Zwischenräume, as the Germans say - are as important as any of the solid parts. Andreas Reinhard articulates the idea rather nicely. "Normally," he says, "whatever you blow, it becomes a sphere or a cylinder, as you know from childhood." But the membranes bind together layers of material so that they take on specific contours as they fill with air. Many of these materials, moreover, gain strength as they are put under tension. Deflated, they are soft and pliable. Inflated, they are rigid and durable. The contours change as the pressure is varied. An inflatable wing can be made to bend almost as naturally as a bird's. Combine these computer-modeled membrane constructions with the dreams of Leonardo da Vinci, and men can fly or build castles in the sky. "I'd like to introduce membranes with air as the sixth construction material," says Thallemer. "Stone, wood, leather, metal, glass - and then air."
Combine Festo's membranes with the dreams of da Vinci, And men can fly. Minuscule robotic fingers with fluidic muscles might help clear away clots or kill cancers.
Thallemer works in the center of Festo's hometown, Esslingen, a wattle-and-daub city near Stuttgart that's so quaint it could be a cuckoo clock. When I visited him, he and his design team were preparing to exhibit several prototype projects at Germany's Hannover Fair trade show. Up three flights of worn stairs, under the exposed rafters of a building whose foundations predate da Vinci, among cluttered desks where anachronism and futurism collide, Thallemer unrolled artists' renderings and elaborate schematics. There was a sketch of something he calls an Airfish. It's basically a blimp, but the form is elongated - thick and round toward the middle then stretched and tapered fore and aft. The silhouette was oddly familiar, organic, but not, I thought, a fish. "A penguin," he said.
This airship concept, which promises more aerodynamic stability and speed than traditional designs, is derived from bionic studies of penguins flying, as it were, underwater. Also on the drawing board were various ambitious Airtecture plans: a vast inflatable theater dubbed Pneumatrix that, if it is ever constructed, might hold as many as 1,000 people; and an off-beach floating sports field - essentially a puffed-up basketball court - called AirOnAqua. But even as Thallemer readied his latest fluidic muscle-bound babies for Hannover, it was impossible for him, or anyone, to predict whether Festo would give these innovations the long-term support necessary to win acceptance on the market and, eventually, a place in daily life.
Many of Festo's Hannover exhibits are playthings. Putting on the Airhopper sport shoe would be like jumping on an amusement park ride, since the little fluidic muscle attached to the back of the boot gives pogo-stick energy to every step. The Citycyc and the Airbug are something more. The first looks like a rickshaw, its locomotion coming from compressed air stored in two 9-liter carbon bottles that are about the size of the steel tanks used in scuba diving, yet weigh only 4.4 kilograms each. The engine is similar to a regular three-cylinder, two-stroke powerplant, but the pistons and cylinders have been replaced by three pneumatic muscles. Another muscle built into the wishbone suspension serves as a shock absorber, and allows for precise adjustment of the Citycyc's clearance. There's no internal combustion, so no pollution. The only noise it makes is a soft, high-speed pocketa-pocketa. And the fuel - air - is "utterly cheap," as Thallemer puts it. For little shopping trips it would be brilliant, especially in European towns with narrow streets and scant parking.
The Airbug is "a six-legged autonomous walking beetle" with a pneumatic muscle attached to each limb. Engineered and programmed (by software subcontractors at FZI, the Forschungszentrum für Informatik, in Karlsruhe) to move like an insect, it's another air-powered creation that imitates ancient laws of nature with new materials and technologies. Variants on the Airbug might include a minefield-clearing machine, or a Mars rover. The earthly off-road experience of four-wheel drive could be replaced by six-leg drive, or something positively centipedal.
Thallemer and Lorenz are looking at medical applications for Festo's technology, since the muscles can now be produced in diameters as small as 1 millimeter. Prosthetic limbs with artificial muscles are an obvious possibility. But the muscles could be used in infinitely delicate surgical procedures such as angioplasty and the isolation of tumors. Minuscule robotic fingers with fluidic muscles might help clear away clots or kill cancers.
Are we entering a New Pneumatic Age? Well, let's take a breath here.
About 10 years ago, Wilfried Stoll, the younger of Festo's brother-owners, decided it was time to freshen up the corporate image. The major players in the industry are few - the Japanese company SMC, the US manufacturers Parker and Numatics, and the Europeans IMI Norgren and Bosch-Rexroth. Competition is ferocious, not least because pistons and tubes all look pretty much the same. The multimillion-dollar distinctions among pneumatic actuators are almost indiscernible. Patent attorneys have made fortunes trying to tell them apart, and since 1988 Festo has been waging an epic lawsuit - Festo Corp. v. Shoketsu Kinzoku Koygo Kabushiki Co. Ltd. - against SMC over a magnetized piston, and has reportedly retained Kenneth Starr to take the case to the US Supreme Court if necessary. When product, price, delivery time, and customer service are all more or less equal, what's left to distinguish one company from another? Well, the fun stuff.
Wilfried wanted to put Festo on the map. More than that, he wanted to rethink the power of air. Working at first with Reinhard, then with Thallemer, who was recruited from Porsche in 1994 to oversee the look of Festo's future, the normally press-shy Wilfried backed projects that were eccentric and amusing. A hot air balloon launched in 1994 appeared to float upside down. Stingray, a flying machine with inflatable silver manta wings, soared in 1996, and the wheezing Airtecture exhibit hall opened the same year.
But visionaries, rather like prophets, don't often find honor in their own companies. At times Festo's team of dreamers has been isolated, even reviled. The conservatism of the rigidly Protestant burghers in this corner of Germany is notorious even among Germans. Notwithstanding Wilfried's ambitions for air, and the publicity some of his flamboyant projects generate, Festo's corporate culture is tightly sealed. The company reveals nothing to the world about its profits and losses, its market share, or its overall strategy. One of its few explicit goals is "to remain an independent, family-owned company." Neither Kurt nor Wilfried give interviews, but the company's designers and inventors are wont to say they're backed by "50 percent of Festo's capital" - meaning Wilfried. The implication being that Kurt is not impressed.
Reinhard remembers that when he and Wilfried started kicking around inflatable fantasies back in 1991, Wilfried seemed to be coming to Switzerland on the sly, and happy to keep their work under wraps. As for Thallemer, his corporate design department once had 20 people in it, but now, apart from secretaries, there are only 3. Thallemer himself - 41 years old and oddly dapper, with white-collared shirts, straggling ties, unruly hair - sometimes gets a slightly out-of-focus, Andy Kaufmanesque look in his eyes. Born into the relatively hedonistic Germany of Bavaria, he clearly doesn't feel at home in Swabia. There is, he says, constant friction with Festo's old guard, with unions that think design projects cost them their bonuses, with the hundreds of people developing traditional pfffttt machines in the traditional R&D teams. They criticize everything from Thallemer's Italian car to his, well, inflated ideas.
Thallemer is neither an engineer nor an industrial designer. Wilfried hired him to explore potential markets for existing working models, to show how the best fantasy can become a practical reality. But both inside and outside the company, Thallemer has to overcome what people think they know about inflatable architecture and pneumatic technologies.
Jules Verne's pneumatic dreams had a limp comeback in the 1960s. The age of pop was also the age of plastics, of inflatable furniture that could help liberate the masses. This "pneumatic Utopia," as Thallemer calls it, was based more on manifestos than manufacturing. Each retro revival of those old inner-tube-like armchairs undermines his mission. From the blow-up dinosaurs at American discount gas stations to designer Nick Crosbie's pumped-up salad bowls, the technology and materials involved are about the same as those in an air mattress. Last year's AirAir show in Monaco seemed to play the whole concept of inflatable design for laughs, with a filmography that recalled the killer sphere in the old TV series The Prisoner and the enormous pneumatic boob pursuing Woody Allen in Everything You Always Wanted to Know About Sex.
Festo is serious, even about its jokes. The upside-down hot air balloon of 1994 was a technical marvel. Constructed by Britain's Cameron Balloons (which also built the Breitling Orbiter 3 that finally circumnavigated the world), it was really a balloon within a balloon: The logos were painted upside down on the exterior one, and a nonfunctional basket was attached to the top. When it was launched, Reinhard remembers, "there were more than 900 calls to the emergency number." Indeed, nobody who saw it forgot the Festo name. And while the first Stingray, now referred to as the baby Stingray, may have had a certain Michelin Man allure around the midsection, the mantalike wings of a second, larger model, now under development, will be filled with helium. The craft won't need a runway; it can be pushed aloft by a built-in compressed-air launcher - a technology that has been successfully tested on an ultralight plane. Possible uses for the Stingray technologies range from surveillance aircraft to commuter planes.
Thallemer is eager to gain attention for Festo's more recent innovations. But, inevitably, he has to admit that the company's main goal, first and foremost and for the foreseeable future, is to serve established customers. One example is Karl Widmann Schweissmaschinen GmbH, a maker of punch cards that switched to the fluidic muscle because it punches holes faster and better than pneumatic actuators. Notwithstanding the promise of the Citycyc, AirBug, and Airtecture, Festo's muscle technology could dead-end as nothing more than a replacement for the piston and tube.
I had the disturbing feeling after my time in Esslingen that Thallemer saw many of his dreams being subsumed by Festo's core business and conservative traditions. At the same time, he'd made me a believer. Why not build our future on the promise of air power? Granted that the engineering behind the new devices is enormously complicated, the result feels reassuringly simple, natural, humanly comprehensible. My taste for imaginative pneumatics was sharpened; I craved more than Thallemer's sketches or his embattled enthusiasms could satisfy. I wanted to hold the things in my hand, or be held by them. So I gave Reinhard another call.
A few days later, I made the long drive to the little farming village of St. Stephan, near the end of a cul-de-sac valley in the Swiss Alps. On the other side of a nearby mountain lies all the chic of Gstaad. On this side, there are no great ski slopes, zero tourists, lots of cows, flocks of sheep, a scattering of chalets that are year-round homes, and a runway big enough for an Airbus. There is also a collection of enormous hangars and subterranean barracks carved out of the mountainside. Most are hidden from public view by camouflage-painted doors capable of withstanding high-explosive blasts. They were built for the Swiss air force. Now the whole base is leased by the 45-year-old Reinhard, who is a former test pilot. Tall, lanky, and balding, he had a strip of adhesive over the bridge of his nose to clear away morning stuffiness. He's every bit the eccentric inventor or Swiss farmer, or both. "Welcome," he said, "to our playground."
Reinhard pulled open the door of the main hangar and led me into the first subterranean chamber. His incredible flying machines were sitting around on blocks. The baby Stingray was pumped up just enough to sustain its structure. Another project, a folding ultralight, dragged the tips of its wings on the floor like an exhausted albatross. All the planes needed was a bit more air - much less than you'd put in a tire - and they would be ready for the runway. Reinhard put his hand lightly on the Stingray's wings like a father caressing the shoulder of his child.
Reinhard still collaborates with Wilfried Stoll, but the inventor is pursuing his own projects, too. He's working on a flight suit that could radically improve conditions for fighter pilots who suffer massive g forces in today's ultrafast combat conditions. Another creation, a pneumatic downhill-skiing simulator, struck me as the perfect diversion for the nightspots of Gstaad.
Interesting stuff. Fun stuff. But as Reinhard showed me around, I knew it was not the really fun stuff. I wanted to see every corner of this bunker full of floating dreams. "There's something else," I said, and Reinhard smiled.
In a workshop, he picked up a stack of what looked like flat, rubberized pieces of fabric with little nozzles on the ends. As he injected compressed air into them, one by one, they contorted into elaborately wrought curves. "We have hundreds of shapes," he said. Then he showed me the cross section of the prototype for an aluminum-covered airfoil. It seemed conventional - until air was pumped into membranes beneath its surface, which made it bend with the contoured nuance of a peregrine's wing. Was this the future of airplane design?
We passed into the next subterranean chamber. Reinhard drew aside a muslin curtain. Behind it was an inflatable boat, nothing like the Zodiac and its ilk, as smooth and shapely as if it were crafted from fiberglass. In the center of the room, a fairly ordinary-looking blimp was crammed between floor and ceiling, ready to fly the minute it left the hangar.
The blimp was a scale model, said Reinhard, part of a much larger project that was still under development. He couldn't tell me more, but he promised that when it was finished, with Festo's help, it would truly be a castle in the air.
The underground bunker was silent. I heard myself sigh.