Inventions that will help save the world (if we let them)

Mark Ostow

Menachem Elimelech, one of Yale engineering’s more commercially successful inventors, has designed devices that use osmosis to purify water, generate electricty, and perform other functions. Above, he holds an osmotic membrane. View full image

“It’s the dream of every engineer to create something useful,” says Menachem Elimelech, inventor of an osmosis system that cleanses water of salt, particulates, and other materials. His technology is now being studied and developed as far away as China, Singapore, and Australia, thanks to a Yale spin-off company, Oasys, founded in 2009. After 23 years in academia, says Elimelech, “this is the first time I’ve had something being commercialized.” As chair of Oasys’s scientific advisory board, he is an active participant in the company’s technological progress, yet he’s free to focus on his work at Yale.

Elimelech is one of the more commercially successful inventors at Yale’s School of Engineering. But his experience shows that even when commercialization works, and works well, it can still produce something quite different from what the inventor envisioned. 

The Oasys system is a relatively cheap way to draw fresh water out of salty water. Most laypeople think of osmosis as doing the opposite. Fresh water is on one side of a membrane, saltier water on the other. The membrane is semipermeable, with holes that allow water molecules to pass through but not salt molecules. Fresh water will flow through the membrane and into the saltier solution, until the two volumes of water are equally salty.

The Oasys system also uses two volumes of water, but both are salty. One, saltier than the other, attracts water molecules. The breakthrough arrived at by Elimelech and his then–doctoral student Rob McGinnis ’02, ’09PhD, was to use novel kinds of salt in the saltier solution. For instance, a concentrated solution of water and ammonium carbonate will draw water molecules out of seawater. Once the solutions are equally concentrated, the ammonium carbonate can simply be decomposed, into ammonia and carbon dioxide, and evaporated away with low-grade heat. What remains is fresh water. (After this article was published, McGinnis wrote to dispute our account of who discovered the desalination process. Read his letter, Eleimelich’s response, and our conclusion.)

In 2011, Elimelech and his colleagues at Oasys told the radio journalists of Living on Earth that their primary goal was to turn seawater into fresh drinking water—a resource expected to become increasingly scarce in the future. But today, the Oasys system is used in fracking. The process of hydraulic fracturing to release underground oil and gas uses a great deal of clean water and produces a tremendous amount of wastewater—wastewater with five times the saline concentration of seawater, even as oil and gas producers need a steady supply of clean water in order to keep drilling. The Oasys system can reduce water disposal volumes by more than 80 percent, cutting the total cost of water treatment by up to 30 percent, and allow the treated wastewater to enter local groundwater safely. It’s an environmental improvement to fracking. But it’s not the municipal water source that Elimelech originally envisioned.

“Everything done at Yale was groundwork,” says Lisa Sorgini Marchewka, vice president of strategy and marketing for Oasys, “but how to actually create a product you can ship to a customer is the greatest challenge. How do you take something to a commercial scale without adding cost or complexity or losing its original intended value?”

The Oasys system is being used in the Permian Basin in Texas, where 500,000 barrels of water are needed to fracture just one well. In such arid regions, anything that increases the supply of usable water, affordably, is in demand. The company is also just beginning to work on producing clean water in the Middle East, using low heat from power plants and geothermal sources.

Meanwhile, Elimelech continues to work on new osmosis technologies. In late 2012, he and a colleague, Chinedum Osuji, received $2.6 million from the US Department of Energy to develop a new invention from concept to product. The technology will use waste heat from industrial facilities, power plants, or geothermal sources to drive an osmosis process that produces electricity—potentially creating a substantial new energy source, and one that constantly recycles the water it depends on. The DOE grant came from a program that funds “breakthrough technologies that show fundamental technical promise but are too early for private-sector investment.” It’s a program, one might say, that helps great inventions make it across the Valley of Death.

Despite the failure of his birth control method, Mark Saltzman has had his successes. Most notable is a drug delivery system he created for brain tumors, with the help of a team of engineers and surgeons: a tiny polymer wafer, impregnated with powerful therapeutic drugs, that can be inserted into the brain and will dissolve there—releasing the drugs at the precise rate needed for maximum benefit. The wafers were approved by the Food and Drug Administration in 1996, and Saltzman is proud of the fact that they are now used throughout the world. “It’s the best you can do, the standard for many brain tumors. It’s my most important contribution,” he says. How much money did he make? Even though Saltzman partnered with a drug company on the work, he says he never made anything on the sale of the devices. “I think others did. I just wanted to do something important and useful.”

OCR is working with Saltzman and his colleague Tarek Fahmy, an associate professor of biomedical engineering, on a project that uses drug nanoparticles released through an FDA-approved polymer. “We’ve been putting a lot of effort into licensing this technology, for cancer vaccines, for infectious disease vaccines, for allergy vaccines and cancer drugs,” says OCR’s Puziss. One company, BIND Therapeutics, has a product that is now entering Phase II clinical trials for cancer.

Saltzman’s latest project, due to begin clinical testing at Yale soon, is a new way to deliver nanoparticles, loaded with drugs, directly into the brain for patients with glioblastoma multiforme—a deadly brain cancer that typically kills patients, as it did the late Senator Ted Kennedy, within a few months. He relishes its many challenges. “You’re designing within constraints. You can’t just pick any drug. You can’t just choose any material. The nanoparticles must be a certain size and have a certain surface chemistry. So how do you optimize with all the constraints? That’s what engineers do.”