At this year’s MADMEC competition held on October 10th an economical hydrogel capable of extracting uranium from water to provide additional fuel for nuclear power plants was bestowed the top prize.
A team of MIT Materials Science and Engineering Students, named A Salt Solution, won $10,000 for a model of a simple, low-cost hydrogel that can be added into water desalination plants or placed straightaway into bodies of water. Uranium then collects on the hydrogel’s surface for extraction.
Similar hydrogels — which are strings of hydrophilic polymer chains — have been suggested for uranium mining in seawater. But the team worked on a certain polymer that can be bought at industrial scales for much lower costs.
Because it’s simple to make, and [based on an already] well-developed technology with a slight modification, it’s an economically feasible material that can passively collect uranium from water.
Cynthia Lo, Team Member
The second and third place prizes of $7,000 and $5,000 went to two other teams. One team was Dumbledore, which is creating an automated wrinkling-and-unwrinkling coating for ships that can stop bacteria and other organisms more efficiently and with less pollution than other techniques. The other team was Geoworks, which is building porous bricks composed of geopolymers (minerals that are mixed and gel together to form solid materials) that can insulate buildings at reduced cost and with better efficiency than traditional insulating materials.
The fourth competing team, Illumination, created a lower-cost material for producing blue light, which can be adapted for lighting and other applications.
Uranium from the sea
Uranium mined from the earth is used as fuel in nuclear power, which is one of the most efficient forms of energy. But there is approximately 4 billion tons of uranium in seawater, compared to 10 million tons on land. In fact, gathering the entire ocean’s uranium could technically provide sufficient material to power major cities worldwide for thousands of years.
A Salt Solution’s idea struck them when they were conceptualizing a material that could be attached to sea coral to gather uranium. But that was too expensive and difficult to fulfill for the competition. To keep the costs manageable, the team adapted a common polymer gel used for other purposes, by adding molecules that attract uranium.
“It looks a little complicated, but it’s pretty simple,” said Team Member William “Robin” Lindemann said during the team’s winning presentation, pointing to a projection of the polymer’s chemical makeup. “You can probably [make] it in your basement.”
One idea is to fit a system that has plates of the hydrogel into water desalination plants, where seawater goes through reverse osmosis to create fresh water and waste brine.
This brine is what we want to target, because it [has a] higher concentration of uranium.
Jasmine Harris, Team Member
Before discarding, the brine could flow over the hydrogel plates for uranium extraction. Uranium can also be easily washed off the hydrogel, so the gel can be reused over a dozen times before it becomes economically unusable.
Another idea is to just float the hydrogel on a buoy or straight in bodies of water. “You can probably just put this gel in a cheesecloth bag and let it float [in water], and a couple weeks later you’d end up with a bunch of uranium stuck to it,” Lindemann told MIT News.
With the prize money, the team plans to carry on developing the technology and potentially publish a paper on their findings.
The MADMEC competition is a yearly event hosted by MIT’s Department of Materials Science and Engineering (DMSE) and sponsored by Saint-Gobain and Dow Chemical.
For the finale, four MIT student teams presented oral and poster demonstrations explaining the inventions they had designed over the summer to solve a range of sustainability issues. Starting in June, MADMEC hosts a number of events that walk the competitors through development milestones, such as refining prototypes and feasibility studies. All teams (typically around 10) receive $1,000 to prototype, and the winners of three mini contests win an extra $500 each.
The contest challenges students to construct prototypes of technologies that enhance sustainability in energy, infrastructure, transportation and other sectors.
Really the big picture of the contest is about giving students a chance to develop their own ideas and execute prototypes outside of their normal classwork or research.
Mike Tarkanian, Senior Lecturer in DMSE and Competition Organizer
For the winning team, the MADMEC competition indeed provided a platform for some fast prototyping. “I’ve never had to pull something like this together so quickly,” Lindemann told MIT News. “And the competition drove us to a better end result.”
Contest judges were MIT faculty, alumni from DMSE and representatives from the contest’s sponsoring companies.
Tarkanian also noted that a number of former MADMEC competitors have started companies based on their MADMEC inventions. Clear Motion (formally Levant Power), was the third-place winner at the first MADMEC in 2007 and went on to raise $130 million to build shock absorbers that enhance vehicle handling while producing electricity to enhance complete efficiency. Embr Labs, winner of the 2013 competition, just sold almost half a million dollars’ worth of preorders for its marketable thermoelectric wristband that cools and heats the body.
“What you will see [during the finale] are often early-stage technologies that grow and get bigger and change over time, and turn into real products,” Tarkanian said.