New technique leverages controlled interactions across surfaces to create self-assembled materials with unprecedented complexity
Building nanomaterials with features spanning just billionths of a meter requires extraordinary precision. Scaling up that construction while increasing complexity presents a significant hurdle to the widespread use of such nano-engineered materials.
Now, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have developed a way to efficiently create scalable, multilayer, multi-patterned nanoscale structures with unprecedented complexity.
The Brookhaven team exploited self-assembly, where materials spontaneous snap together to form the desired structure. But they introduced a significant leap in material intelligence, because each self-assembled layer now guides the configuration of additional layers.
Building nanomaterials with features spanning just billionths of a meter requires extraordinary precision. Scaling up that construction while increasing complexity presents a significant hurdle to the widespread use of such nano-engineered materials.
Now, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have developed a way to efficiently create scalable, multilayer, multi-patterned nanoscale structures with unprecedented complexity.
The Brookhaven team exploited self-assembly, where materials spontaneous snap together to form the desired structure. But they introduced a significant leap in material intelligence, because each self-assembled layer now guides the configuration of additional layers.
The results, published in the journal Nature Communications, offer a new paradigm for nanoscale self-assembly, potentially advancing nanotechnology used for medicine, energy generation, and other applications.
“There’s something amazing and rewarding about creating structures no one has ever seen before,” said study coauthor Kevin Yager, a scientist at Brookhaven Lab’s Center for Functional Nanomaterials (CFN). “We’re calling this responsive layering—like building a tower, but where each brick is intelligent and contains instructions for subsequent bricks.”
The technique was pioneered entirely at the CFN, a DOE Office of Science User Facility.
“The trick was chemically ‘sealing’ each layer to make it robust enough that the additional layers don’t disrupt it,” said lead author Atikur Rahman, a Brookhaven Lab postdoc during the study and now an assistant professor at the Indian Institute of Science Education and Research, Pune. “This granted us unprecedented control. We can now stack any sequence of self-organized layers to create increasingly intricate 3D structures.”
Guiding nanoscale conversations
The added color in this scanning electron microscope (SEM) image showcases the discrete, self-assembled layers within these novel nanostructures. The pale blue bars are each roughly 4,000 times thinner than a single human hair.
Other nano-fabrication methods—such as lithography—can create precise nano-structures, but the spontaneous ordering of self-assembly makes it faster and easier. Further, responsive layering pushes that efficiency in new directions, enabling, for example, structures with internal channels or pockets that would be exceedingly difficult to make by any other means.
“Self-assembly is inexpensive and scalable because it’s driven by intrinsic interactions,” said study coauthor and CFN scientist Gregory Doerk. “We avoid the complex tools that are traditionally used to carve precise nano-structures.”
The CFN collaboration used thin films of block copolymers (BCP)—chains of two distinct molecules linked together. Through well-established techniques, the scientists spread BCP films across a substrate, applied heat, and watched the material self-assemble into a prescribed configuration. Imagine spreading LEGOs over a baking sheet, sticking it in the oven, and then seeing it emerge with each piece elegantly snapped together in perfect order.
However, these materials are conventionally two-dimensional, and simply stacking them would yield a disordered mess. So the Brookhaven Lab scientists developed a way to have self-assembled layers discretely “talk” to one another.
The team infused each layer with a vapor of inorganic molecules to seal the structure—a bit like applying nanoscale shellac to preserve a just-assembled puzzle.
“We tuned the vapor infiltration step so that each layer’s structure exhibits controlled surface contours,” Rahman said. “Subsequent layers then feel and respond to this subtle topography.”
Coauthor Pawel Majewski added, “Essentially, we open up a ‘conversation’ between layers. The surface patterns drive a kind of topographic crosstalk, and each layer acts as a template for the next one.”
Exotic configurations
An aerial view of a complete, self-assembled, multilayer nanostructure. In this instance, parallel bars of block copolymers with varying thickness were criss-crossed.
As often occurs in fundamental research, this crosstalk was an unexpected phenomenon.
“We were amazed when we first saw templated ordering from one layer to the next, Rahman said. “We knew immediately that we had to exhaustively test all the possible combinations of film layers and explore the technique’s potential.”
The collaboration demonstrated the formation of a broad range of nano-structures—including many configurations never before observed. Some contained hollow chambers, round pegs, rods, and winding shapes.
“This was really a Herculean effort on the part of Atikur,” Yager said. “The multi-layer samples covered a staggering range of combinations.”
Mapping never-before-seen structures
This image shows the range of multilayer morphologies achieved through this new technique. The first column shows a cross section of the novel 3D nanostructures as captured by scanning electron microscopy (SEM). The computer renderings in the second column highlight the integrity and diversity of each distinct layer, while the overhead SEM view of the third column reveals the complex patterns achieved through the “intelligent” layering.
The scientists used scanning electron microscopy (SEM) to probe the nanoscale features, getting cross-sectional details of the emergent structures. A focused electron beam bombarded the sample, bouncing off surface features before being detected to enable reconstruction of an image depicting the exact configuration.
They complemented this with x-ray scattering at Brookhaven’s National Synchrotron Light Source II—another DOE Office of Science User Facility. The penetrative scattering technique allowed the researchers to probe the internal structure.
“CFN brings together a unique concentration of skills, interests, and technology,” said CFN Director and coauthor Charles Black. “In one facility, we have people interested in creating, converting, and measuring structures—that’s how we can have these kinds of unanticipated and highly collaborative breakthroughs.”
This fundamental breakthrough substantially broadens the diversity and complexity of structures that can be made with self-assembly, and correspondingly broadens the range of potential applications. For example, intricate three-dimensional nanostructures could yield transformative improvements in nano-porous membranes for water purification, bio-sensing, or catalysis.
Learn more: Nanoscale ‘Conversations’ Create Complex, Multi-Layered Structures
[osd_subscribe categories=’self-assembling-structures’ placeholder=’Email Address’ button_text=’Subscribe Now for any new posts on the topic “SELF-ASSEMBLING STRUCTURES”‘]
Receive an email update when we add a new SELF-ASSEMBLING STRUCTURES article.
The Latest on: Self-assembling structures
[google_news title=”” keyword=”self-assembling structures” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Self-assembling structures
- Scientists learn from caterpillars how to create self-assembling capsules for drug deliveryon April 26, 2024 at 8:00 am
Self-assembling molecules that spontaneously organize themselves to form complex structures are common in nature. For example, the tough outer layer of insects, called the cuticle, is rich in proteins ...
- Learning from caterpillars to create self-assembling capsules for drug deliveryon April 25, 2024 at 5:00 pm
(Nanowerk News) Self-assembling molecules that spontaneously organise themselves to form complex structures are common in nature. For example, the tough outer layer of insects, called the cuticle, is ...
- This co-op Viking survival game is a lot different to Valheim because you can recruit NPCs, assign them jobs, and occasionally devour their soulson April 25, 2024 at 6:00 am
Build a settlement and assemble a Viking tribe in Aska.
- Quantum forces used to automatically assemble tiny deviceon April 25, 2024 at 1:48 am
The very weak forces of attraction caused by the Casimir effect can now be used to manipulate microscopic gold flakes and turn them into a light-trapping tool ...
- Are these Métis nations’ dreams of self-governance dead? Here’s what we know about the latest developments in a contentious billon April 24, 2024 at 1:00 pm
Bill C-53 has been criticized by First Nations and Métis groups across Canada since it was introduced to Parliament last June.
- Research combines DNA origami and photolithography to move one step closer to molecular computerson April 24, 2024 at 8:49 am
Molecular computer components could represent a new IT revolution and help us create cheaper, faster, smaller, and more powerful computers. Yet researchers struggle to find ways to assemble them more ...
- National Organization for Women's unintentional self-satireon April 24, 2024 at 4:06 am
Everything about this post, from the repeat after us mantra to the silliness of the first sentence and the absurdity of the second sentence, shouts Babylon Bee more than NOW, except that the radical ...
- Self-assembling synthetic cells act like living cells with extra abilitieson April 23, 2024 at 5:00 pm
Cells get their structure and stability from their cytoskeleton ... For the new study, scientists from the University of North Carolina at Chapel Hill developed synthetic, self-assembling ...
- Gaza, Ukraine, and the Breakdown of International Lawon April 22, 2024 at 9:02 pm
International humanitarian law, also known as the law of war or the law of armed conflict, is supposed to spare civilians from the worst calamities of conflict. The aim of this body of law has always ...
via Bing News