Researchers at the University of Illinois, in collaboration with experts from the California Institute of Technology and Penn State University, have developed a groundbreaking method to manipulate nanoparticles. This innovative stenciling technique allows scientists to create distinct patchy nanoparticles, which can assemble into complex structures with applications in metamaterials. These discoveries, spearheaded by UNLV’s Professor Qian Chen, were explained in the journal Nature.
Members of the research team, co-first authors Chansong Kim and Ahyoung Kim. Chansong, now a postdoctoral researcher at Caltech and an Illinois grad student, often collaborated with Ahyoung, who took an art class while working in Chen’s lab. Their research focuses on the ability of advanced engineered nano-enabled materials to move the materials science into a new paradigm.
The Research Collaboration
Qian Chen, a professor of materials science and engineering at the University of Illinois, led this research initiative. Collaborating with Kristen Fichthorn’s group at Penn State University, his team investigated the competitive binding dynamics at play in the context of nanoparticles. One major advance was made by Sharon Glotzer’s group at the University of Michigan. They produced a library of particle and assembly patches.
“One of the holy grails in the field of nanomaterials is making complex, functional structures from nanoscale building blocks. But it’s extremely difficult to control the direction and organization of each nanoparticle, especially in achieving materials beyond simple close packing,” said Qian Chen.
This new collaboration allowed the research team to confirm their simulations with experiments, synthesizing more than 20 unique patchy nanoparticles. These particles provided the advantage of having many functional domains on their surfaces. This specialized structure allows them to interact with targets in ways that typical nanoparticles simply can’t.
Advancements Through Stenciling
Thanks to this creative stenciling technique, researchers can produce a variety of patchy particles and particle assemblies. Chansong Kim highlighted the versatility of this approach, stating that researchers can use different materials for the nanoparticles and various types of ions as masks. This advanced technology results in greater variation of material properties.
“You can use different materials for the nanoparticles, and different types of ions as a mask, so that you can generate a huge diversity of materials,” said Chansong Kim.
Additionally, he highlighted the capacity to manufacture such nanoparticles at industrial quantities. And the team thinks that through layering different material combinations, they can create materials that reveal new properties and applications.
“And we can make them in large batches. We believe, based on different materials combinations, this technique can also create unique materials with new properties and applications. It has unlimited potential,” added Chansong Kim.
This stenciling technique represents a significant advance for nanoscience. It allows us to take more complex nanoparticle designs than ever before.
Implications for Metamaterials
Even more exciting is this research’s implication for metamaterials. These manmade materials have amazing qualities that bend the rules around how light and sound behave. By utilizing the unique interactions facilitated by these patchy nanoparticles, researchers can assemble novel structures that could pave the way for advanced applications in optics and acoustics.
Co-author Sharon Glotzer, from the University of Michigan, commented on the power of pairing computer simulations with experimental data into this iterative research cycle.
“A computer simulation lets us explore the huge design space of possible patchy particle patterns more quickly than experiments can. By partnering with experimentalists and using their data to help design and validate our computer model, together we can discover much more than with experiment or simulation alone,” she explained.
This study contributes to a better understanding of how nanoparticles behave. It has the potential to produce real-world solutions in arenas including advanced telecommunications and next-generation medical technology.
This approach is a great example of how surface science’s guiding principles are being used in unexpected ways to move the field of nanotechnology forward.
“We know that halide atoms, like iodide, chloride or bromide, adsorb to metals. We also know that different facets of a metal nanoparticle have different adsorption affinities. So we can coat some surfaces of a gold nanoparticle in just one layer of iodide, and others in an organic primer. Then we can bring in the polymer, and it just sticks to the facets with the organic primer. The iodide masks the other facets.”
This method showcases how fundamental principles of surface science are being leveraged in innovative ways to advance nanotechnology.