Overview
- Icy roads are synonymous with Michigan winter, and the Washtenaw County Road Commission uses about 18,000 tons of salt in an average year to keep the roads safe and the local economy humming. The WCRC reported using 3.1 million pounds of salt during just one heavy snowstorm in 2019, costing more than $80,000 in salt costs alone.
- The mobility benefits of salt for a car-centric society, though, have an undesirable environmental side effect that has built up over decades of use: extensive damage to ecosystems and infrastructure. “You can think of chloride as a permanent pollutant in the water,” said Christe Alwin of the Michigan Department of Environment, Great Lakes, and Energy. “Once it’s there, there’s very little opportunity to treat it.” Aquatic life like stoneflies and freshwater mussels perish in salty water, affecting the diets of species higher up the food chain. Road salt also weaken infrastructure by aging bridges, cement, and vehicles. (Source: *directly quoted* https://www.greatlakesnow.org/2023/01/road-salt-damaging-michigan-waters/)
- Feasible road salt alternatives have proven elusive. Calcium chloride and magnesium chloride, which have fewer environmental issues (and less corrosive to vehicles), are very expensive compared to salt. Sugar beet juice smells awful. Whey brine, a cheese byproduct, and pickle juice have been tried, but they have to be applied to dryroads before ice forms.
- New, nontoxic materials could one day keep solar panels and airplane wings ice-free, or protect first responders from frostbite and more, thanks to a new University of Michigan-led project funded by the Defense Advanced Research Projects Agency. “For the past seven or eight years now, my group has been making surfaces that have very low adhesion to ice. Such ice-shedding coatings can be very useful for a number of applications such as wind turbines, power lines or airplane wings,” said Anish Tuteja, the project’s principal investigator and a professor of materials science and engineering at the University of Michigan. Spraying planes with de-icing fluids ensures that winter flights stay safe, but the chemicals in such fluids are toxic and can also pollute waterways. And some of what the researchers aim to make with the up to $11.5 million project has no current analogue, like a lotion that protects from frostbite without heavy winter layers. (Source: *directly quoted* https://news.engin.umich.edu/2024/01/beating-the-freeze-up-to-11-5m-for-eco-friendly-control-over-ice-and-snow/)
- Now the group of researchers is looking to nature for molecules that act as natural antifreezes. To meet their goals, the research team is looking at plants, animals and microbes that survive by producing molecules that allow them to freeze solid or stop their bodies from freezing. One animal of interest is the Wood frog, a species native to Washtenaw County that freezes solid and thaws in the spring. The frog produces antifreeze lipids that prevent ice from damaging their cell membranes when they freeze over the winter.
- Other organisms being studied produce “ice-nucleating” molecules that stimulate ice to form at warmer than usual temperatures. The bacterium Pseudomonas syringae produces ice-nucleating proteins to freeze plant leaves. The ice helps break apart plant cells so that the bacterium can access the nutrients inside.
- Mixtures of molecules that occur in nature could hold the key to an environmentally safe alternative to road salt. Computer-aided modeling is helping to narrow down the millions of combinations possible to determine the few that are most likely to be successful so that they can be tested.
- The research team must measure the effectiveness of over 5,000 different ice-forming and antifreeze molecules within the first year of the project. That number could double or triple as the project progresses. To quickly study these molecular combos, the team plans to build an automated platform to determine the freezing temperatures of as many as 1,500 samples a day. The team hopes to narrow its search down to the 30 most promising candidate molecules for further study by the end of their first year.(Source: *directly quoted* https://news.engin.umich.edu/2024/01/beating-the-freeze-up-to-11-5m-for-eco-friendly-control-over-ice-and-snow/)
- In the second year of the project, the team will test each candidate molecule’s safety and toxicity as well as its effectiveness at larger scales and in several forms, such as liquids, creams and coatings. These experiments will not only help the researchers find the best antifreeze and ice-forming mixtures—the large dataset will also help reveal how different ice-forming and ice-inhibiting molecules do their jobs. https://news.engin.umich.edu/2024/01/beating-the-freeze-up-to-11-5m-for-eco-friendly-control-over-ice-and-snow/)
Transcription
David Fair: This is 89 one WEMU, and welcome to another edition of Issues of the Environment. I'm David Fair, and this week, we're going to get some insights into new research that seeks to find a cost-effective and environmentally friendly alternative to the salt we use to deice our roadways and other deicing practices. Where better to look for that than in nature? The University of Michigan is leading an $11.5 million study to find solutions. Our guest today is Anish Tuteja. He is a professor of materials science and engineering at the University of Michigan and serves as the project's principal investigator. Thank you so much for joining us today, Anish.
Anish Tuteja: Thank you very much, David. Thank you for having me.
David Fair: First of all, to get the environmental perspective, how negatively do things like road salt, plane deicing chemicals and other ice-fighting products impact the environment?
Anish Tuteja: There are many sort of negative consequences--environmental consequences--that are associated with the use of road salt, particularly in these bulk quantities. So, there's a lot of challenges. One of the simpler, but simplest one is to think about the corrosion that the salt might cause on any of the associated structures. But then, there are much more sort of environmental impacts. So, that road salt can slowly seep into the water. There's also other sort of really interesting challenges. For example, because the salt is attractive to things like deer. So, deer of course like to lick salt.
David Fair: Right.
Anish Tuteja: There's a higher chance of these things actually coming into accidents, as they sort of start to lick the salt on the roadway. And then, of course, you can have an accident based on that. And then, there's a lot of other smaller animals where this high concentration of salt is actually toxic to them. So, there is a big need for sort of more environmentally friendly solutions that are also cheap.
David Fair: Certainly, looking for materials that help create a non-adhesive surface for ice is nothing new to you. You've been looking into that for some years now. What degree of success have you had?
Anish Tuteja: We've had a lot of really nice work in that area. And we've been working ,in the last maybe 7 or 8 years, for different coatings that can prevent the adhesion, or at least reduce the adhesion, of ice significantly. And we've been fairly successful. So, that technology has been licensed out of the university and is being commercialized. It's already been applied to a few high-rises, solar panels, where we essentially preventing the accumulation of snow and ice, during the winter on high-rises, preventing the accretion of large structures of ice that can fall down and hit pedestrians and such. So, a lot of scale-up has happened, and it's continuing to happen. And we hopefully will keep seeing more and more applications of these in the future.
David Fair: So, what makes this study and research project different than the research paths you followed to this point?
Anish Tuteja: Yeah. So, it's really interesting. So far, we've been looking at, "Okay, so if I have snow and ice, that's going to come down and attach onto a surface, how do I make it easier to remove back snow and ice?" Now, we're sort of trying to tackle a different problem. How about I prevent snow and ice from forming in the first place, or at least delay it significantly? And that has a lot of applications, certainly, in preventing the buildup of ice and snow on roadways, but other things as well that people may not be familiar with. For example, deicing cycles are commonly happening in every refrigerator in the world, every freezer in the world, heat pumps--that's a huge energy drain. The efficiency of heat pumps goes down significantly as we're putting them in different buildings in a colder environment. And the efficiency of all of these things can be improved significantly if you could prevent freezing from happening in the first place. So, that's where we are hoping to get to, at least either completely prevent freezing, but even if we can't get there, to significantly delay when freezing happens on a surface or in solution, which again has a ton of applications, whether we're thinking of medicines or I.V. bags that are used in cold environments, preventing frostbite from happening for, maybe, the homeless population that might be exposed to a cold environment. So, tons of applications of preventing freezing from happening in the first place, as opposed to shedding ice and snow once it's already attached onto a surface.
David Fair: Our Issues of the Environment conversation with Anish Tuteja continues on 89 one WEMU. And, Anish, the research team is looking to plants, animals and microbes to find solutions looking to nature. Have you identified which of each in nature is best suited to research?
Anish Tuteja: Yeah. Great question, David. So, it was really fascinating to me as we learned about many of these organisms in the Arctic. So, we have things like wood frogs and beetles and fish where you can go down to -40 Celsius or -60 Celsius in some cases. And the blood of these organisms does not freeze. And they have been looking at different molecules and combinations of molecules. So, these are all biodegradable molecules that already exist in nature. They've identified unique combinations of different molecules that can achieve this very amazing property of preventing the freezing of their blood and allowing these organisms to survive the really brutal winter. And so, over the last 50 years, people have identified a few different molecules, different things called antifreeze proteins or antifreeze glycol lipids. But the challenge is, only in the last 50 plus years, we've only been able to identify a few of these molecules. And typically, each organism has multiple of these molecules. And they're typically acting or are utilized in combination with other smaller molecules. So, it's not just these individual molecules. They're typically combinations of molecules. And so far, it's been really hard for people to identify these combinations of molecules. So, the combinations of molecules is really important. And the ratios or the relative concentration of each of those molecules in that mixture is also really important because many times these things have synergistic effects. So, if one molecule, let's say, reduces the freezing point of water by five degrees and another one reduces it by seven degrees, but you combine them in the right ratio, it might reduce it by 15 degrees. And those combinations are completely unknown. So, we have hundreds of molecules and thousands and maybe millions of combinations. How do you go about identifying the right combination and the right ratio? And that's what we're hoping to do in this project.
David Fair: Let's take that research down the line somewhat. Let's say you find some solution in the wood frogs. Would the plan be to create massive wood frog farms around the country to produce the needed materials, or would you have to look at ways to synthetically produce what the frogs create naturally?
Anish Tuteja: Great question, David. Yes. So, our goal is to have everything done synthetically. So, we are not going to be removing any of these molecules from actual wood frogs. That's been done in the past. And so, we already know the sorts of molecules that exist and what the structure of those molecules are. So, everything will be done synthetically, because we are very, very sort of aware of the environmental impact that something like this can have. So, we have a lot of candidate molecules that are already widely available, a lot that we're synthesizing within the laboratory. And then, we screen through these combinations.
David Fair: This is 89 one WEMU's Issues of the Environment. And we're talking with University of Michigan professor and researcher Anish Tuteja about the search for deicing materials that are environmentally friendly. Now, in my unscientific mind, my perception is that when mankind tries to synthetically reproduce nature, we become a bigger threat to nature. How do you offset that potential?
Anish Tuteja: That's a great, great point, David. A significant portion of the work is looking at the environmental impact and toxicity of any of the molecules that we produce and any combinations of molecules that we produce. And so, we have experts within the team whose entire portion of the project is going to be looking at the environmental impact or potential environmental impact and toxicity of any of the molecules or combinations that we produce. What's also interesting is we have an ELSI expert within the team, which is the ethical, legal and societal implications of the project. And throughout the project, over the next two and a half years, we will be interviewing any person that is likely to be impacted by some of these materials, particularly indigenous tribes in the Arctic, that might be impacted by any of this research in the future or any sort of stakeholders throughout the colder regions of the country that may be impacted. And so, the goal is to both look at sort of the technical side of this and really looking at what are the toxicity issues that might be associated with any of these molecules, but also looking at sort of the ethical implications of this. And now that we are sort of using these bio-derived molecules, even though we're no longer extracting them, let's say, from wood frogs, they originally were identified in these species. So, what are the ethical and moral sort of issues that come from that?
David Fair: Well, again, this is a study funded by the Defense Advanced Research Projects Agency, or DARPA, as it's called. Its mission is creating breakthrough technologies and capabilities for national security. So, my first thought was whatever you find is something they might want to weaponize or to enhance wartime efforts. Did that ever cross your mind?
Anish Tuteja: DARPA funds a lot of different types of research. It's not always about sort of weaponizing those. And I mean, again, I can't speak for DARPA and what exactly they want to do kind of utilize this research for. Our sort of purpose is to really explore the unique science that comes in this sort of environment and things that are going to be widely utilized by the society.
David Fair: So, let's go further down that path. I know you have to go where the science takes you, but do you have an expectation of particular outcomes or a hypothesis of where it lands you?
Anish Tuteja: Not at the moment. So, this is supposed to be in the basic science sort of category of research. This is not aimed in any way for a specific application or a D.O.D. application that's coming out of it. This is really supposed to be aimed at understanding new mechanisms and really understanding the science behind how these things work.
David Fair: Well, I want to thank you for the time and sharing the information today, Anish. And I'm looking forward to seeing where this all takes us. It sounds like there were a lot of wonderful potential applications.
Anish Tuteja: Thank you very much, David. It was wonderful to speak with you.
David Fair: That is Anish Tuteja. He is professor of material science and engineering at the University of Michigan and principal investigator in a study aimed at finding some new deicing solutions in nature. For more information on this study, visit our website at wemu.org. Issues of the environment is produced in partnership with the office of the Washtenaw County Water Resources Commissioner, and you hear it every Wednesday. I'm David Fair, and this is your community NPR station, 89 one WEMU FM Ypsilanti.
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