With atomic stenciling, researchers have made quite a lot of patterned patchy nanoparticles with new shapes and properties. Credit: Maayan Harel.
Oct 20, 2025
UNIVERSITY PARK, Pa. — Inspired by an artist’s stencils, researchers have developed atomic-level precision patterning on nanoparticle surfaces, permitting them to “paint” gold nanoparticles with polymers, or lengthy chains of small molecules, to offer them an array of recent shapes and features. The “patchy nanoparticles” developed by a multi-institutional crew that features researchers at Penn State will be made in giant batches, used for quite a lot of digital, optical or biomedical functions, or used as constructing blocks for brand new complicated supplies and metamaterials.
Co-led by Kristen Fichthorn, Merrell Fenske Professor of Chemical Engineering and professor of physics at Penn State, the crew consists of collaborators on the University of Illinois Urbana-Champaign and the University of Michigan. The researchers reported their findings within the journal Nature.
“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,” stated co-corresponding creator Qian Chen, professor of supplies science and engineering on the University of Illinois Urbana-Champaign. “Then we got this idea from nature: Proteins have different surface domains, and by their interaction, they can make all the intricate machines we see in biology. So, we are adopting that strategy, having patches or distinct domains on the surface of the nanoparticles.”
However, the issue of the right way to connect the patches in a managed design or at giant scales proved a problem, the researchers stated. While wrestling with the issue as a graduate pupil in Chen’s lab, Ahyoung Kim, the co-first creator of the paper, took an artwork class. In the category, she discovered a stenciling method that used a masks to color a fancy design on a curved piece of pottery. She realized such a way may work on nanoparticle surfaces, too.
Working with Chen, Fichthorn’s group employed quantum mechanical calculations to develop masking designs by exploring the aggressive binding of iodide and natural primer to faceted gold nanoparticles.
“Ionic adsorption is a classical question in surface science,” Fichthorn stated, explaining that adsorption is the binding of atoms and molecules to a strong floor. “We computed, at the atomic level, the energetically preferred configurations of iodide and organic primer on various gold facets and predicted a phase diagram for atomic stenciling to occur.”
“We know that halide atoms, like iodide, chloride or bromide, adsorb to metals,” stated Kim, who’s now a postdoctoral researcher on the California Institute of Technology. “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 sticks just to the facets with the organic primer. The iodide masks the other facets.” The researchers partnered with Michigan Professor Sharon Glotzer’s group to create a library of the sorts of patchy particles and assemblies the stenciling method may yield. They used pc simulations to foretell how the polymers would prepare inside the stencil patterns, after which how the ensuing patchy particles would prepare into bigger crystal buildings. Chen’s group validated the simulations experimentally, making greater than 20 distinct patchy nanoparticles.
“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,” Glotzer stated. “Atomic stenciling allows for the synthesis of batches of patchy particles with far more intricate patterns than have been possible in the last 25 years of nanoscience research and will make it easier to self-assemble increasingly more sophisticated structures from nanoparticles.”
Because the particles have a number of practical areas on their surfaces, they work together in methods different nanoparticles can not, and so they assemble into novel buildings with potential for metamaterials — engineered supplies with distinctive gentle and sound properties — stated Illinois graduate pupil Chansong Kim, a co-first creator of the paper. Additionally, he stated, the masking method may apply to many different sorts of nanoparticles and practical teams, not solely gold and polymer.
“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,” Chansong Kim stated. “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.”
Other Penn State-affiliated authors of the examine are Eun Mi Kim and Junseok Kim, each of whom have been graduate college students within the Robert V. Waltemeyer Department of Chemical Engineering on the time of the analysis. Other main collaborator establishments on the work embrace the David Muller group at Cornell University and Aaron Michelson at Brookhaven National Laboratory.
The U.S. Department of Energy supported the experimental work by means of grant DE-SC0020723. Glotzer’s collaboration with Chen was supported by the U. S. National Science Foundation by means of the Complex Particle Systems Science and Technology Center.
Fichthorn’s work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Materials Science Division, Grant DE FG02-07ER46414. Computing sources have been supplied by the Pittsburgh Supercomputing Center by means of allocation DMR110061 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) program.
Editor’s word: A model of this text first appeared on the University of Illinois Urbana-Champaign’s site.