Drexel Joins $ 7.4 Million European Research Council Project to Assemble Nanomaterials for Artificial Muscles, Separation Membranes and Flexible Structural Batteries  

Researchers from Drexel University and the University of Toulouse in France will lead an international effort to develop a new type of matter that exists somewhere on the spectrum between a solid and a liquid. The ambitious project is supported by a $7.4 million (€ 6,625,661) grant from the European Research Council, with the hope that the breakthroughs in fundamental science it generates will one day be used to create technologies such as high-performance filtration and separation membranes, flexible and structural batteries and electrochemical capacitors, and even artificial muscles.

The European Research Council’s € 500 million Synergy Grant program is intended to foster collaboration between researchers at different universities in pursuit of breakthrough scientific discoveries. This year, the highly competitive program will support 50 projects from nearly 1,000 submitted across all disciplines of scientific research.

Drexel and Toulouse’s project will establish a new approach to nanomaterials engineering that could present solid-liquid materials — dubbed “SLiMs” by the research team — as a solution to a range of the world’s most pressing energy and sustainability challenges.

“Being chosen to participate in this program with colleagues from the University of Toulouse for whom I have deep respect and with whom we have produced a great deal of highly impactful research is a true honor,” said Yury Gogotsi, PhD, Distinguished University and Bach chair professor in Drexel’s Nick Howley College of Engineering and Computing’s School of Engineering, who will lead Drexel’s participation in the research. “With ERC support driving what has already been a fruitful collaboration, we anticipate a new generation of assembled nanomaterials to appear on the horizon through this work.”

The project will draw on developments in materials science generated through prior collaborations between Gogotsi and his counterpart in Toulouse, Patrice Simon, PhD. Over the last two decades, the duo has published more than 50 papers in peer-reviewed journals on the frontiers of nanomaterials and electrochemistry — including the most cited paper in the field of electrochemical capacitors, which has been cited more than 20,000 times to date.

Their latest collaboration will take place over the next six years with the aim of creating conformal, yet structurally robust materials that conduct ions and electrons and can be electronically manipulated, called solid-liquid materials. The duo will be joined by Toulouse team member Céline Merlet, PhD, who will use artificial intelligence and computational methods to accelerate nanomaterials development and select the optimal combinations of nanometer-thin nanosheets and the ions and molecules that connect them.

“I am extremely grateful to the European Research Council for funding the SLiMs project. This project will first enable us to develop a new generation of programmable materials, combining electronic and mechanical properties that can be activated and controlled electrochemically,” Simon said. “Beyond this scientific ambition, I am particularly delighted to continue my scientific collaboration with Prof. Yury Gogotsi, which we initiated more than 20 years ago. Yury is a scientist for whom I have the deepest respect, both for his outstanding scientific contributions and for the person he is.”

Their approach will draw on Gogotsi’s extensive research on MXenes, the family of 2D materials he and his collaborators discovered at Drexel in 2011, marking the first major inorganic material family discovered in the 21st century. Over the last 15 years, his research group has steadily revealed the potential of these versatile materials. Due to their layered atomic structure, metallic conductivity, and durability, MXenes of varying compositions have found applications ranging from chemical filtration to electromagnetic shielding.

Gogotsi and Simon’s team have also developed several ways to produce these nanomaterials, enabling precise control of their flake size, structure, and chemical composition. They can be manufactured by selective etching and delamination as nanometer-thin, water-dispersible flakes, grown through chemical vapor deposition, and turned into inks and paints.

To produce a material that flows like a liquid one moment and congeals into a substance as strong as steel the next, the team plans to capitalize on MXenes’ unique ability to encapsulate electrolytes, such as ionic liquids, between their 2D sheets.

Gogotsi and Simon describe 2D MXene nanosheets as the “bricks” and ionic liquid as the “mortar” to assemble solid-liquid material structures. Because each element can be chemically engineered to produce a specific mechanical or physical behavior, the researchers suggest that the materials will be “fully programmable.” They anticipate tailoring the materials to filter liquids at the ion level and create rigid structural materials that can also store energy.

“These material behaviors are on the periphery of our current knowledge,” Simon said. “This project will push the boundaries of what it means for a material to be a liquid or a solid, which will create exciting new applications such as structural batteries, smart membranes and electrochemical actuators.”

Simon, whose lab is among the world’s top research centers for studying and characterizing the electrochemical foundations that enable a material’s mechanical properties, has regularly contributed his expertise to help explain and guide Gogotsi’s team’s efforts to develop and study new carbon and MXene materials for batteries, supercapacitors, capacitive water deionization and other electrochemical applications.

Selecting the right ionic liquid or another electrolyte to pair with the corresponding MXene material is key to the endeavor, as this interaction drives the material’s physical and electrochemical properties — from durability to electrical conductivity.

“There are so many combinations it would take an eternity to explore all of them,” Gogotsi said. “We are counting on our collaborators in Toulouse to help us unlock the mechanisms of MXene’s extraordinary behavior and direct us toward fruitful new lines of inquiry and discovery.”

To help navigate the complexities of finding just the right liquid-nanomaterial combination, the team will turn to Merlet, who is a researcher at France’s National Centre for Scientific Research and an expert in simulations of energy storage materials. Merlet’s team will harness artificial intelligence and machine learning technology to parse massive volumes of scientific data and project the properties of yet-to-be-created materials and combinations of 2D nanosheets and electrolytes through multi-scale simulations of the systems.

“Our goal is to identify and simulate the electrochemical systems that produce unique characteristics of solid-liquid materials — like conductivity or mechanical rigidity,” Merlet said. “By linking these behaviors to electrochemical properties, we will be able to fine-tune the materials — at the atomic level — for very specific uses.”

The researchers envision solid-liquid materials being used for tasks that require regular shifting between the two material states and among various physical properties. This could include making water filters that can dynamically tune themselves to filter out an ever-changing range of contaminants; actuators and robotic skins; or shape-morphing materials for airplanes and structural energy storage materials for electric vehicles.

“This is just the beginning of an exciting new journey to materials of the future,” Gogotsi said. “We believe this project will lead to a paradigm change in materials assembly and design, as we use mobile molecules and ions confined within conductive, strong 2D solids to build materials that can be ionotronically modulated to change their properties and shape, respond to their environment and, ultimately, enable technologies that have only been possible in science fiction novels so far.”