“What we wanted to explore in this article is how social science research practices can be adapted, even reinvented, to harness the power of AI,” said Igor Grossmann, professor of psychology at Waterloo.

Grossmann and colleagues note that large language models trained on vast amounts of text data are increasingly capable of simulating human-like responses and behaviours. This offers novel opportunities for testing theories and hypotheses about human behaviour at great scale and speed.

Traditionally, social sciences rely on a range of methods, including questionnaires, behavioral tests, observational studies, and experiments. A common goal in social science research is to obtain a generalized representation of characteristics of individuals, groups, cultures, and their dynamics. With the advent of advanced AI systems, the landscape of data collection in social sciences may shift.

“AI models can represent a vast array of human experiences and perspectives, possibly giving them a higher degree of freedom to generate diverse responses than conventional human participant methods, which can help to reduce generalizability concerns in research,” said Grossmann.

“LLMs might supplant human participants for data collection,” said UPenn psychology professor Philip Tetlock. “In fact, LLMs have already demonstrated their ability to generate realistic survey responses concerning consumer behaviour. Large language models will revolutionize human-based forecasting in the next 3 years. It won’t make sense for humans unassisted by AIs to venture probabilistic judgments in serious policy debates. I put an 90% chance on that. Of course, how humans react to all of that is another matter.”

While opinions on the feasibility of this application of advanced AI systems vary, studies using simulated participants could be used to generate novel hypotheses that could then be confirmed in human populations.

But the researchers warn of some of the possible pitfalls in this approach — including the fact that LLMs are often trained to exclude socio-cultural biases that exist for real-life humans. This means that sociologists using AI in this way couldn’t study those biases.

Professor Dawn Parker, a co-author on the article from the University of Waterloo, notes that researchers will need to establish guidelines for the governance of LLMs in research.

“Pragmatic concerns with data quality, fairness, and equity of access to the powerful AI systems will be substantial,” Parker said. “So, we must ensure that social science LLMs, like all scientific models, are open-source, meaning that their algorithms and ideally data are available to all to scrutinize, test, and modify. Only by maintaining transparency and replicability can we ensure that AI-assisted social science research truly contributes to our understanding of human experience.”

Promoting national security and economic competitiveness will require America’s researchers to find new ways to obtain the materials that we need for many technologies. These include batteries, magnets in electric motors, catalysts, nuclear reactors and other essential carbon-free energy technologies.

Water represents one underexplored avenue of acquiring these materials. Scientists at the U.S. Department of Energy’s Argonne National Laboratory have recently published a comprehensive review detailing the various mechanisms by which critical materials can be extracted from diverse water streams.

Different types of water offer different kinds of material resources, said Seth Darling, chief science and technology officer for Argonne’s Advanced Energy Technologies directorate. ​”The oceans are such a tremendous resource because the total quantities of many valuable and important materials are vast, but they are also highly dilute,” he said. ​”Wastewater has also been in need of reframing — we want people to see that wastewater is not truly waste, rather, it’s rich with all sorts of valuable stuff.”

Darling also pointed to groundwater aquifers and geothermal brines as other possible sources of valuable materials. These materials include lithium, which is increasingly in demand for electric vehicle batteries and could be used to help decarbonize our economy. ​”Lithium is in the ocean and in geothermal brines; you’d extract it differently from these two sources but it’s important to understand which is cheapest, has the smallest environmental impact, and enables secure supply chains,” Darling said. ​”For many other materials, water is underexplored as a source, and that’s something we’re paying increasingly more attention to.”

The technologies that Darling and his colleagues are exploring to extract critical materials from different types of water range from the traditional (like membranes) to the innovative (like interfacial solar steam generators).

Omar Kazi, a Ph.D. student in molecular engineering at the University of Chicago working with Darling, is studying methods to concentrate wastewater streams to recover valuable materials. ​”Getting rid of the water through evaporation is an energy-intensive and slow process,” Kazi said. ​”In geothermal brines, it can take years for water to evaporate to be able to recover the lithium that’s contained in them, which creates a huge bottleneck. The question we are asking is ​’how we can make the water evaporate faster?'”

One way to do that could be through the use of porous photothermal materials, which convert light to heat efficiently. These light absorbers act like a black T-shirt that heats up on a sunny day. That heat is transferred to the water directly at the interface with the surrounding air, significantly accelerating evaporation.

Overall, Darling noted, Argonne has rich capabilities in supply chain, life cycle and technoeconomic analyses. In addition, the laboratory specializes in the materials, chemistry and process engineering relevant to critical material extraction. This uniquely positions the lab to help achieve a more secure and circular economy of materials, especially when it comes to getting more out of water streams.

A paper based on the study, ​”Material design strategies for recovery of critical resources from water,” appeared online in Advanced Materials on March 31.

In addition to Darling and Kazi, other authors of the study include Argonne’s Wen Chen, Jamila Eatman, Feng Gao, Yining Liu, Yuqin Wang, and Zijing Xia.

This work was supported as part of the Advanced Materials for Energy-Water Systems (AMEWS) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences at Argonne National Laboratory.

At the latest, the Russia-Ukraine conflict revealed loud and clear that the global food supply chain acts as a complex network, connecting nations and facilitating the spread of disruptions from local to distant regions. “However, previous studies often focus on direct dependencies and overlook indirect dependencies resulting from the unavailability of essential inputs, making a comprehensive assessment of the global food system difficult,” emphasizes research director Stefan Thurner of the Complexity Science Hub.

INDIRECT EFFECTS OFTEN EXCEED DIRECT EFFECTS

To bridge this gap, the research team developed a dynamic global food system model, incorporating data from 192 countries and territories and encompassing 125 food and agricultural products. “This model enabled us to simulate shocks to specific products and countries, closely monitoring the subsequent effects across the entire supply chain,” explains Moritz Laber of the Complexity Science Hub. By quantifying the relative reduction in product availability compared to a baseline scenario (without the shock), the researchers gained valuable insights into the magnitude of these shocks. Remarkably, they found that indirect effects often exceeded direct effects. For example, a shock to Ukrainian corn production led to a 13% decline in pork availability in Southern Europe. In comparison, a shock to Ukrainian pork production had a negligible effect of less than 1%.

UP TO 85% LOSS OF MAIZE

In a worst-case scenario simulation, where agricultural production in Ukraine was completely lost due to the Russia-Ukraine conflict, the study unveiled diverse effects on products and regions worldwide. “The loss of grains, particularly maize, reached up to 85%, while edible oils, especially sunflower oil, experienced losses of up to 89%. Additionally, certain meat types, such as poultry, suffered losses of up to 25% in various countries,” says Laber. The number of products for which a region is dependent on Ukraine varies greatly: Southern Europe is the most affected, with 19 out of 125 products with losses of more than 10%, followed by West Asia and North Africa, where this is the case for 15 and 11 products respectively.

These findings emphasize that localized production disruptions have far-reaching implications, extending beyond geographic boundaries through trade relationships and the entire production chain. Consequently, it is imperative to consider both direct and indirect effects when estimating losses and formulating effective interventions.

RISK NOT ONLY FROM WARS

As the Russia-Ukraine conflict enters its second year, food prices are still above 2021 levels, according to the European Council. In addition, various events, including extreme weather events, economic crises, and geopolitical tensions, can trigger similar disruptions. This underscores the importance of exploring interdependencies within global food supply chains and gaining a comprehensive understanding of the direct and indirect impacts of local shocks to raise awareness among policymakers and stakeholders of otherwise overlooked risks within the global food system.

These research findings are a valuable first leap in understanding the complex dynamics of global food supply chains and their vulnerability to local shocks. Further research is needed to map them at a more granular level considering individual products and subnational scales at a higher temporal resolution. Moreover, at present, the model assumes that countries do not change their trading partners after a shock. However, restructuring trade relations may exacerbate existing inequalities, as wealthier countries may secure remaining resources at higher prices from alternative suppliers.

In March, the CSH co-founded the Austrian Supply Chain Intelligence Institute (ASCII) to contribute even more to making supply dependencies visible in the future.

Some implants are hard and bulky, while others are flexible and thin. But no matter their form and function, nearly all implants incorporate electrodes — small conductive elements that attach directly to target tissues to electrically stimulate muscles and nerves.

Implantable electrodes are predominantly made from rigid metals that are electrically conductive by nature. But over time, metals can aggravate tissues, causing scarring and inflammation that in turn can degrade an implant’s performance.

Now, MIT engineers have developed a metal-free, jelly-like material that is as soft and tough as biological tissue and can conduct electricity similarly to conventional metals. The material can be made into a printable ink, which the researchers patterned into flexible, rubbery electrodes. The new material, which is a type of high-performance conducting polymer hydrogel, may one day replace metals as functional, gel-based electrodes, with the look and feel of biological tissue.

“This material operates the same as metal electrodes but is made from gels that are similar to our bodies, and with similar water content,” says Hyunwoo Yuk SM ’16 PhD ’21, co-founder of SanaHeal, a medical device startup. “It’s like an artificial tissue or nerve.”

“We believe that for the first time, we have a tough, robust, Jell-O-like electrode that can potentially replace metal to stimulate nerves and interface with the heart, brain, and other organs in the body,” adds Xuanhe Zhao, professor of mechanical engineering and of civil and environmental engineering at MIT.

Zhao, Yuk, and others at MIT and elsewhere report their results in Nature Materials. The study’s co-authors include first author and former MIT postdoc Tao Zhou, who is now an assistant professor at Penn State University, and colleagues at Jiangxi Science and Technology Normal University and Shanghai Jiao Tong University.

A true challenge

The vast majority of polymers are insulating by nature, meaning that electricity does not pass easily through them. But there exists a small and special class of polymers that can in fact pass electrons through their bulk. Some conductive polymers were first shown to exhibit high electrical conductivity in the 1970s — work that was later awarded a Nobel Prize in Chemistry.

Recently, researchers including those in Zhao’s lab have tried using conductive polymers to fabricate soft, metal-free electrodes for use in bioelectronic implants and other medical devices. These efforts have aimed to make soft yet tough, electrically conductive films and patches, primarily by mixing particles of conductive polymers, with hydrogel — a type of soft and spongy water-rich polymer.

Researchers hoped the combination of conductive polymer and hydrogel would yield a flexible, biocompatible, and electrically conductive gel. But the materials made to date were either too weak and brittle, or they exhibited poor electrical performance.

“In gel materials, the electrical and mechanical properties always fight each other,” Yuk says. “If you improve a gel’s electrical properties, you have to sacrifice mechanical properties, and vice versa. But in reality, we need both: A material should be conductive, and also stretchy and robust. That was the true challenge and the reason why people could not make conductive polymers into reliable devices entirely made out of gel.”

Electric spaghetti

In their new study, Yuk and his colleagues found they needed a new recipe to mix conductive polymers with hydrogels in a way that enhanced both the electrical and mechanical properties of the respective ingredients.

“People previously relied on homogenous, random mixing of the two materials,” Yuk says.

Such mixtures produced gels made of randomly dispersed polymer particles. The group realized that to preserve the electrical and mechanical strengths of the conductive polymer and the hydrogel respectively, both ingredients should be mixed in a way that they slightly repel — a state known as phase separation. In this slightly separated state, each ingredient could then link its respective polymers to form long, microscopic strands, while also mixing as a whole.

“Imagine we are making electrical and mechanical spaghetti,” Zhao offers. “The electrical spaghetti is the conductive polymer, which can now transmit electricity across the material because it is continuous. And the mechanical spaghetti is the hydrogel, which can transmit mechanical forces and be tough and stretchy because it is also continuous.”

The researchers then tweaked the recipe to cook the spaghettified gel into an ink, which they fed through a 3D printer, and printed onto films of pure hydrogel, in patterns similar to conventional metal electrodes.

“Because this gel is 3D-printable, we can customize geometries and shapes, which makes it easy to fabricate electrical interfaces for all kinds of organs,” says first-author Zhou.

The researchers then implanted the printed, Jell-O-like electrodes onto the heart, sciatic nerve, and spinal cord of rats. The team tested the electrodes’ electrical and mechanical performance in the animals for up to two months and found the devices remained stable throughout, with little inflammation or scarring to the surrounding tissues. The electrodes also were able to relay electrical pulses from the heart to an external monitor, as well as deliver small pulses to the sciatic nerve and spinal cord, which in turn stimulated motor activity in the associated muscles and limbs.

Going forward, Yuk envisions that an immediate application for the new material may be for people recovering from heart surgery.

“These patients need a few weeks of electrical support to avoid heart attack as a side effect of surgery,” Yuk says. “So, doctors stitch a metallic electrode on the surface of the heart and stimulate it over weeks. We may replace those metal electrodes with our gel to minimize complications and side effects that people currently just accept.”

The team is working to extend the material’s lifetime and performance. Then, the gel could be used as a soft electrical interface between organs and longer-term implants, including pacemakers and deep-brain stimulators.

“The goal of our group is to replace glass, ceramic, and metal inside the body, with something like Jell-O so it’s more benign but better performance, and can last a long time,” Zhao says. “That’s our hope.”

This research is supported, in part, by the National Institutes of Health.