Flying High – The Role of the Cleanroom in the Development of Flying Cars

A few months ago, we came across a promotion for an animal shelter in which adorably adoptable dogs were air-lifted to potential families using state-of-the-art drones. Readied in a NASA-style flight suit, each pooch was custom delivered to a suburban back yard, frolicking with delighted children in the lush green grass under the contented gaze of their parents.(1) And, although impractical, it’s a cute concept: a new family member, ‘ordered’ from your local shelter through an app, and delivered via drone to your front door like an Amazon parcel. Could this ever really be the future of flying transportation?

Not really. But if you substitute the idea of the drone for that of a flying car…now you might be onto something.

Flying cars? Have we lost our minds?

Not at all. Bear with us because although the concept might still seem way too far-fetched right now, the technology is not. And the reason why autonomous aerial vehicles – or AAVs – might be closer than you think is very simple: battery power. In 2010 and 2015 Larry Paige, the co-founder of Google, invested heavily in a couple of start-up companies, which aim to bring flying cars to the masses. Zee Aero and Kitty Hawk, along with Uber, Joby Aviation, and other key players, are developing prototype vehicles that use the same technology currently deployed in helicopters to take off and land. But unlike helicopters – with their single gigantic rotor – Vertical Take-Off and Landing (VTOL) technology makes use of a series of smaller vertical propellers that raise the vehicle into the air and provide vertical thrust. Once the vehicle has attained cruising altitude, the propellers fold up neatly to streamline the craft, enhance airflow dynamics, and save power.

And this last point – saving power – is the critical component, the game changer in aeronautical technology. In Joby Aviation’s S2, two-seater craft, the VTOL requires up to five times less power than conventional combustion, while travelling five times faster. And the batteries that make this concept a reality are produced by Tesla, already a key player in the semiautonomous vehicle market. In a previous article, ‘Keeping Our Hands on the Wheel: Should We Resist the Rise of the Robots?’,we discussed Tesla’s emerging dominance in self-driving car manufacturing and its use of home-grown technologies, including an investment in lithium-ion technology. In the market for flying cars, the production of an energy-dense lithium-ion (LI) cell is critical, offering the opportunity to power a vehicle further – or with a greater payload – on a single charge. In a Vox article by Timothy B. Lee, ‘Why Google co-founder Larry Paige is pouring millions into flying cars,’ Brian German, an aerospace researcher at Georgia Tech, is noted as saying: “Right now, batteries that you could actually put in an airplane wouldn’t let you fly very far. But give it a few more years, and the writing’s on the wall that you will be able to make a very practical aircraft.”(2)

And this is true as long as it’s lithium-ion batteries we are talking about. At this stage it’s safe to assume this is precisely what Tesla CEO Elon Musk has in mind with the development of his Gigafactory – the world’s largest LI battery plant – out in the Nevada desert. With a construction price tag of around $5 billion, Tesla’s projected 10 million square feet factory is roughly 50% finished, and will employ 6,500 workers when complete. The Gigafactory – the first of its kind – is projected to net the State of Nevada $100 billion in economic gain over two decades, adding 4% to that state’s GDP.(3) And given that the increase in battery efficiency is set rise by 5%-8% per year you can bet that Tesla is playing the long game, eyeing the broader range of applications for its technology.

But that’s not all.

From a contamination-control perspective, possibly the most exciting aspect of this story is Tesla’s commitment to the construction of a series of custom cleanrooms

in which to develop its products. Partnering with Panasonic, the aim of the Gigafactory is the manufacturing and supply of cylindrical lithium-ion batteries as components of the much-vaunted stationary powerpacks for solar energy storage and fuel modules for the iconic S3, Tesla’s all-electric family sedan. And without even taking into account the future market of airborne cars, the volume of batteries necessary to meet the existing demand for mass market electric vehicles equates to Tesla producing the equivalent of ‘today’s entire worldwide production of lithium ion batteries.’(4) Scarcely a small task and one that also brings with it inherently a significant complication: lithium reactivity.

An alkali metal, lithium is a soft, flammable, highly reactive element that accounts for 0.0007% of the earth’s crust.(5) As the least dense solid element it is the lightest of all metals and reacts with air to form oxides and with water to create hydroxides. Its diverse uses include weaponization in thermonuclear devices, energy production in nuclear fusion reactions, and pharmacological embraces in the treatment of bipolar disease and severe depression. But it in the production of batteries that lithium truly excels, albeit at some cost. In order to work with this element on such a grand scale, Tesla must develop a suite of cleanroom and dryrooms that conform to ISO Class 6 and 7 and maintain below 1–10% Relative Humidity (RH) and a Dew Point of -40° to -50° Fahrenheit.(6) These specifications are critical because, when placed in contact with water, lithium reacts to produce lithium hydroxide (an extremely corrosive compound) and hydrogen gas, burning with a bright orange flame. In contact with air, the element will not only form lithium hydroxide but also lithium nitride (from its interaction with nitrogen in the air) and lithium carbonate (from the carbon dioxide in the air). In addition, it will combust, burning with a fierce red flame.

And in a gigantic production environment, all of this reactivity must be handled extremely sensitively. But, according to analysts, given the Gigafactory’s potential for economies of scale, the payoffs will be worth it. In current terms, the cost of LI battery production is approximately $190 per kilowatt hour (kWh). Once Tesla’s Nevada facility is up to speed in production, that cost will be cut a full 30% to an estimated $130/kWh. And, as the technology moves beyond Tesla’s own brand vehicles and into the AAV market, that cost could be passed on to the commuter pool. How? Let’s take a closer look…

Although wide scale adoption of the concept will, in time, lower the cost, it’s very doubtful that AAV technology will replace the automobile for an average consumer. Entertaining as it might be, we’re unlikely to see our neighbors investing in their own Jetson car in the short term. What’s more likely is that companies with an on-demand transportation business model will deploy AAVs as a top-tier product – enabling customers to pay a premium for an air taxi that would raise them above the rush hour congestion and get them from point A to point B in a fraction of the time. Take Uber, for instance. Founded in 2009 and now available in over 66 countries and 545 cities, Uber is arguably one of the best-known faces of an app-based enterprise that’s effectively disrupting the transportation industry. And as such it is well positioned as an authority on the future of AAV taxis. In a recent white paper, Uber made a claim that’s sure to be warmly welcomed by anyone who’s suffered the misfortune of sitting in California’s notorious rush hour gridlock. According to that company’s analysis, an aerial taxi could whisk a time-strapped commuter from San Jose to San Francisco – a journey of some 55 miles – in approximately 15 minutes. Compare that with the 90 – 120 minute journey on terra firma. And, as increased adoption drives down the cost of battery power, the tariff for that trip could plummet from a projected initial $129 to just $43.(7)

All of which sounds great. With that kind of price tag, the use of AAVs could soon be easily within the reach of both premier travellers and the middle-class alike, and the frustrations of lengthy commutes could be a thing of the past. But before you fire up that Uber app, there’s a plethora of potential issues to deal with before we can start scheduling our next (non-) roadtrip. As we already know from ‘Automotive Cleanrooms: A Contradiction in Terms?’, failure to control contamination in manufacturing can be extremely costly to the automotive industry. According to an article by Hosco, a finishing system components manufacturer based in Wixom, MI, the main use of a cleanroom in the automotive industry is to prevent contamination – dust particles, lint, hair, skin flakes, etc – from ruining an expensive paint job.(8) According to authors S. Thomas Boyce and Jan Pitzer, 60% of all potential contamination is brought into a cleanroom environment by the workers themselves, with the remaining 40% of dirt sources coming from paint particles, color ‘carry-over’ between jobs, and residue from cleaning solutions within the paint lines.(9) And while anyone in the contamination-control industry can sympathize with the problem, defects in earth-bound cars are rarely fatal, causing only a fiscal dent in baseline profits when a visual defect necessitates a re-spray.

But contamination control is much more of a concern when the vehicles are designed to travel the airways above highly populated metropolitan areas. When their take-off and landing areas are, of necessity, going to be limited to specifically-designated ‘vertiports’ atop high-rise buildings or parking lots. When they are flying five times faster than ground-based autos. When the failure of sensitive equipment like a sensor or a lithium-ion battery could result in a terminal loss of the vehicle and all of those aboard…and below.

Which is why the nascent industry needs a considerable amount of analysis before we ever start seeing flying cars. Key players will need to market the solution to a public reluctant to take to the skies in small, potentially pilotless craft instead of hitting the highway.

Manufacturers will be forced to develop über-stringent SOPs, cGMPs, protocols, and cleanroom technologies to ensure that their components are as defect-free as possible.

And the Federal Aviation Authorities (FAA) will have a significant amount of data to sift through before any kind of AAV regulation can be set in place. And then there’s the question of how to regulate the tens – or perhaps hundreds – of thousands of low-flying aircraft that will inundate the skies.

But as with any emerging industry, the challenges will birth the solutions. Manufacturers will find ways to consistently improve their products and the FAA will identify ways in which to lower the risk to users. In a statement, FAA officials said they are taking “a flexible, open-minded, and risk-based approach” to the concept and that the agency believes “automation technology already being prototyped in low-risk, unmanned aircraft missions, when fully mature, could have a positive effect [on flying car safety].”(10) And when that happens, that 15 minute ‘drive’ from Silicon Valley to the Golden Gate Bridge won’t seem to grueling after all.

Are you excited at the prospect of flying cars? Would you take the risk? Or do you prefer to remain behind the wheel on terra firma? We’d love to know your thoughts!

References:

1. https://youtu.be/kUNU3GRT9SE
2. http://www.vox.com/new-money/2016/12/30/14105960/flying-car-future-explained
3. https://www.bloomberg.com/news/articles/2014-09-05/nevada-expects-100-billion-impact-from-tesla-factory
4. https://www.cleanroomtechnology.com/news/article_page/Building_the_worlds_biggest_lithium_ion_battery_plant/119947
5. https://chem.libretexts.org/Core/Inorganic_Chemistry/Descriptive_Chemistry/Elements_Organized_by_Block/1_s-Block_Elements/Group__1%3A_The_Alkali_Metals/Chemistry_of_Lithium
6. https://www.cleanroomtechnology.com/news/article_page/Building_the_worlds_biggest_lithium_ion_battery_plant/119947
7. https://www.ireviews.com/news/2017/01/02/silicon-valley-perfecting-the-flying-car
8. https://www.hosco.net/sites/default/files/How%20Clean%20are%20Paint%20Shop%20Cleanrooms.pdf
9. ibid
10. http://www.heraldtribune.com/news/20170130/flying-cars-increasingly-feasible