A Simple Israeli Invention Could Help 2.5 Billion People – and NASA

Science usually advances in small steps. Each new experiment adds a small scrap of information. It’s rare for a simple idea that arises in a scientist’s brain, without the use of any technology, to lead to a significant breakthrough. But that’s what happened to two Israeli engineers who developed a new way to make optical lenses.

The system is simple, cheap and precise, and could have a dramatic impact on up to a third of the world’s population. It could also change the face of space research. And to devise it, all the researchers needed was a whiteboard, a marker, an eraser and a bit of luck.

Prof. Moran Bercovici and Dr. Valeri Frumkin, both from the mechanical engineering department at the Technion – Israel Institute of Technology in Haifa, specialize in fluid mechanics, not optics. But a year and a half ago, at a World Laureates Forum conference in Shanghai, Bercovici happened to be sitting with economist David Zilberman, who is originally from Israel.

Zilberman, a Wolf Prize laureate who is now at the University of California, Berkeley, talked about his research in developing countries. Bercovici described his experiments with fluids. And then Zilberman asked a simple question: “Can you make glasses out of this?”

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Lenses produced with the technique developed by Prof. Moran Bercovici and Dr. Valeri Frumkin.

“Why do you ask?” Bercovici replied. Zilberman’s answer astounded him.

“When you think about developing countries, you usually think about malaria, wars, hunger,” Bercovici says. “But Zilberman said something  I was totally unaware of – that there are 2.5 billion people in the world who need glasses but have no access to them. That’s an astounding figure.”

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Dr. Valeri Frumkin.Credit: Courtesy of Dr. Valeri Frumkin.

Bercovici returned home and found a World Economic Forum report that confirmed this number. Although making a simple pair of glasses costs just a few dollars, in large parts of the world, cheap glasses are neither made nor sold. 

The impact is enormous, from children who can’t see the blackboard in school to adults whose vision deteriorates so badly that they lose their jobs. And besides the harm to people’s quality of life, the cost to the global economy has been estimated at $3 trillion a year.

Bercovici couldn’t sleep at night after the conversation. When he arrived at the Technion, he discussed the issue with Frumkin, who was then a postdoctoral researcher in his lab. 

“We drew a lens on the whiteboard and looked at it,” he recalls. “We knew instinctively that we couldn’t make this shape with our technique for controlling fluids, and we wanted to find out why.”

The answer, he says with a smile, “was that annoying thing called gravity.”

Spherical shapes are the basis for optics, since lenses are made from them. In theory, Bercovici and Frumkin knew that they could take polymers, which are liquids that have solidified, and make round domes from them, thereby creating lenses. But liquids maintain a spherical shape only at tiny volumes. At larger volumes, the force of gravity flattens them into a puddle.

“So what we had to do was get rid of gravity,” Bercovici explains. 
And that’s exactly what he and Frumkin did. After studying their whiteboard, Frumkin came up with an idea so simple it’s not clear why nobody ever thought of it before – you can eliminate the effect of gravity if you make the lens inside a liquid chamber. All you have to do is make sure the liquid in the chamber, called the buoyancy liquid, has the same density as the polymer from which you are making the lens, and then the polymer will float.

The other essential thing is to use two fluids that are immiscible, meaning they don’t mix with each other, such as oil and water. “Most polymers are more like oils, so our ‘exotic’ buoyancy liquid is water,” Bercovici said. 

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Research engineer Omer Luria, Prof. Moran Bercovici, and doctoral student Mor Elgarisi.Credit: Rami Shllush

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UV radiation being used in the creation of a lens at the Technion lab, this week.Credit: Rami Shllush

But since water has a lower density than polymers, its density has to be increased a little so the polymer will float. For this, too, the researchers used not-so-exotic materials – salt, sugar or glycerin.
The final ingredient in the process, Bercovici says, is a rigid frame into which the polymer is injected, enabling control over its form.

When the polymer reaches its final form, it is hardened using UV radiation and becomes a solid lens. To create the frames, the researchers used a simple sewage pipe sliced into rings, or Petri dishes from which they  had cut off the bottom. “Any kid could make them at home, and I made some at home with my daughters,” says Bercovici. “We have made a lot of things in the lab over the years, some of them very complex, but this without a doubt was the simplest and most unsophisticated thing we ever did. And perhaps the most important.”

Small, ugly and incredible

Frumkin created his first lens on the same day that he thought of the solution. “He sent me a photo on WhatsApp,” Bercovici recalls. “In retrospect, it was a pretty small and ugly lens, but we were delighted.” Frumkin kept on examining the new invention. “The equations showed that once you remove gravity, it doesn’t matter if the frame is one centimeter in size or one kilometer; you will always receive the same shape, depending on the amount of material.”

The two researchers continued with their experiment with the second generation of secret ingredients – a mop bucket – and used it to create a lens with a diameter of 20 centimeters, suitable for a telescope. The cost of lenses grows exponentially by diameter, but with this new method all that is required, regardless of size, is a cheap polymer, water, salt (or glycerin) and a ring-shaped mold. 

The list of ingredients marks a dramatic turn from the traditional lens-making method that has remained almost unchanged for 300 years.  In the initial stage of the traditional process, a slab of glass or plastic is ground down mechanically. In the manufacture of lenses for glasses, for example, some 80 percent of the material goes to waste. Using the method devised by Bercovici and Frumkin, instead of grinding down solid material, liquid is injected into a frame, creating a lens in a completely waste-free process. This method also removes the need for polishing, as the surface tension of the fluid ensures the creation of an extremely smooth surface.

Haaretz visited the lab at the Technion, where doctoral student Mor Elgarisi demonstrated the process. He injects polymer into a ring inside a small liquid chamber, shines a UV lamp on it, and after two minutes hands me a pair of surgical gloves. Very carefully, I dip my hands into the water and pull out the lens. “That’s it, process over,” Bercovici shouts out. 

The lens is absolutely smooth to touch. It’s not just a subjective feeling: Bercovici says that even without polishing, the surface roughness of a lens manufactured using the polymer method is less than a nanometer (one billionth of a meter). “The forces of nature create extraordinary quality by themselves, for free,” he says. By comparison, optical glasses are polished to a level of 100 nanometers, while the mirrors on NASA’s flagship project, the James Webb Space Telescope, are polished to a level of 20 nanometers.

But not everyone is convinced that this elegant method will be the savior for billions of people around the world. Prof. Ady Arie of the School of Electrical Engineering at Tel Aviv University notes that Bercovici and Frumkin’s method requires a circular mold into which the liquid polymer is injected, the polymer itself, and a UV lamp.

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Mor Elgarisi at the Technion lab, this week.Credit: Rami Shllush

“These aren’t available in villages in India,” he notes. Another problem raised by Niv Adut, founder and VP of R&D at SPO Precision Optics, and by   the company’s chief scientist, Dr. Doron Sturlesi – who are both familiar with Bercovici's work – is that replacing the grinding process with a plastic cast will make it difficult to adapt the lens to the person who needs it. 

Bercovici isn’t alarmed. “Criticism is a fundamental component of science, and our rapid development over the past year was achieved in great measure thanks to experts who pushed us into a corner,” he says. Regarding the feasibility of manufacturing in remote regions, he adds: “The infrastructure required to create glasses using the traditional method is enormous; you need a factory, machines, technicians, while we require only minimal infrastructure.”

Bercovici shows us two UV radiation lamps in his lab: “This one came from Amazon and cost $4, while the other came from AliExpress and cost $1.70. And if you don’t have them, you can always use sunlight,” he explains. And what about the polymer? “A 250-milliliter bottle costs $16 on Amazon. The average lens requires between five to 10 milliliters, so the cost of the polymer isn’t really a factor either.”

He emphasizes that his method also doesn’t require a unique mold for each lens number, as critics have claimed. The simple mold is suitable for each lens number, he explains: “What makes the difference is the amount of polymer injected, and to create a cylinder for glasses all that is required is to stretch the mold a little bit.” 

The only expensive part of the process, says Bercovici, is automation of the polymer injection, which has to be done precisely according to the lens number required.