In early 2023, scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory used autonomous methods can discover new materials. The artificial intelligence (AI)-driven technique led to the discovery of three new nanostructures, including a first-of-its-kind nanoscale ladder.
Scanning-electron microscopy images depict novel nanostructures discovered by artificial intelligence. Researchers describe the patterns as skew (left), alternating lines (center), and ladder (right). Scale bars are 200 nanometers.
Their discovery of the nanoscale ladder and other new structures further widens the scope of self-assembly’s applications.
“Self-assembly can be used as a technique for nanopatterning, which is a driver for advances in microelectronics and computer hardware,” said CFN scientist and co-author Gregory Doerk. “These technologies are always pushing for higher resolution using smaller nanopatterns. You can get really small and tightly controlled features from self-assembling materials, but they do not necessarily obey the kind of rules that we lay out for circuits, for example. By directing self-assembly using a template, we can form patterns that are more useful.”
“The fact that we can now create a ladder structure, which no one has ever dreamed of before, is amazing,” said CFN group leader and co-author Kevin Yager. “Traditional self-assembly can only form relatively simple structures like cylinders, sheets, and spheres. But by blending two materials together and using just the right chemical grating, we’ve found that entirely new structures are possible.”
Blending self-assembling materials together has enabled CFN scientists to uncover unique structures, but it has also created new challenges. With many more parameters to control in the self-assembly process, finding the right combination of parameters to create new and useful structures is a battle against time. To accelerate their research, CFN scientists leveraged a new AI capability: autonomous experimentation.
Plasmonics are special optical phenomena that are understood as interactions between light and matter and possess diverse shapes, material compositions, and symmetry-related behavior. The design of such plasmonic structures at the nanoscale level can pave the way for optical materials that respond to the orientation of light (polarization), which is not easily achievable in bulk size and existing materials.
In a significant leap forward for quantum nanophotonics, a team of European and Israeli physicists has introduced a new type of polaritonic cavities and redefined the limits of light confinement. This pioneering work, detailed in a study published in Nature Materials, demonstrates an unconventional method to confine photons, overcoming the traditional limitations in nanophotonics.
A coating that can hide objects in plain sight, or an implant that behaves exactly like bone tissue—these extraordinary objects are already made from "metamaterials." Researchers from TU Delft have now developed an AI tool that not only can discover such extraordinary materials but also makes them fabrication-ready and durable. This makes it possible to create devices with unprecedented functionalities. They have published their findings in Advanced Materials.
Engineering researchers have developed a 2D printing process using liquid metals that they say could create new ways of creating more advanced and energy efficient computing hardware that is manufactured at the nanoscale.
The process comes amid increasing worldwide demand for memory devices, which require significant amounts of energy to produce and use.
"Reducing the temperature at which zirconium and hafnium become liquid is crucial to developing lower-cost electrical devices as far less energy is required," said Dr. Mohammad Ghasemian, the study's lead author from the School of Chemical and Biomolecular Engineering.
Liquid Lightning: Nanotechnology Unlocks New Energy
MARCH 13, 2024
EPFL researchers have discovered that nanoscale devices harnessing the hydroelectric effect can harvest electricity from the evaporation of fluids with higher ion concentrations than purified water, revealing a vast untapped energy potential.
Evaporation is a natural process so ubiquitous that most of us take it for granted. In fact, roughly half of the solar energy that reaches the earth drives evaporative processes. Since 2017, researchers have been working to harness the energy potential of evaporation via the hydrovol~aic (HV) effect, which allows electricity to be harvested when fluid is passed over the charged surface of a nanoscale device. Evaporation establishes a continuous flow within nanochannels inside these devices, which act as passive pumping mechanisms. This effect is also seen in the microcapillaries of plants, where water transport occurs thanks to a combination of capillary pressure and natural evaporation.
Although hydrovoltaic devices currently exist, there is very little functional understanding of the conditions and physical phenomena that govern HV energy production at the nanoscale. It’s an information gap that Giulia Tagliabue, head of the Laboratory of Nanoscience for Energy Technology (LNET) in the School of Engineering, and PhD student Tarique Anwar wanted to fill. They leveraged a combination of experiments and multiphysics modelling to characterize fluid flows, ion flows, and electrostatic effects due to solid-liquid interactions, with the goal of optimizing HV devices.
“Thanks to our novel, highly controlled platform, this is the first study that quantifies these hydrovoltaic phenomena by highlighting the significance of various interfacial interactions. But in the process, we also made a major finding: that hydrovoltaic devices can operate over a wide range of salinities, contradicting prior understanding that highly purified water was required for best performance,” says Tagliabue.
A printable organic polymer that assembles into chiral structures when printed has enabled researchers to reliably measure the amount of charge produced in spin-to-charge conversion within a spintronic material at room temperature. The polymer's tunable qualities and versatility make it desirable not only for less expensive, environmentally friendly, printable electronic applications, but also for use in understanding chirality and spin interactions more generally.
Spintronic devices are electronic devices that harness the spin of an electron, rather than its charge, to create energy-efficient current used for data storage, communication, and computing. Chiral materials refer to materials that cannot be imposed on their mirror image—think of your left and right hands, for example. If you lay your left hand over your right, the finger positions are reversed. That is chirality.
Chirality in spintronic materials allows designers to control the direction of spin within the material, known as the "chirality-induced spin selectivity (CISS)" effect. The CISS effect occurs when charge current flows along the chiral axis in a chiral material, producing spin—or charge-to-spin conversion—without needing ferromagnetic elements. Charge-to-spin conversion is necessary for memory storage in computing devices.
Making ever smaller and more powerful chips requires new ultrathin materials: 2D materials that are only 1 atom thick, or even just a couple of atoms. Think about graphene or ultra-thin silicon membrane for instance.
Scientists at TU Delft have taken an important step in application of these materials: they can now measure important thermal properties of ultrathin silicon membranes. A major advantage of their method is that no physical contact needs to be made with the membrane, so pristine properties can be measured and no complex fabrication is required.
The findings are published in the journal APL Materials.
Medical implants could fail less often when coated with a microscopically crinkled, ceramic material designed by researchers at the University of Michigan. The coating is described in a paper published in ACS Applied Materials and Interfaces.
The material's very tiny crinkles are the perfect size for young bone cells and immune cells to latch onto. With their firmer grip on the coatings, human cells can strongly adhere to the implant and stretch out along its surface. Stretched bone cells develop faster, and stretched immune cells tend to help heal tissue and reduce inflammation rather than attack the implant as a foreign invader, so the researchers think their coatings could make medical implants more successful.
