DNA data storage plus compute; printed metal oxides; optimizing STM probes.
Researchers from North Carolina State University and Johns Hopkins University created a DNA-based device that can perform both data storage and computing functions.
“Specifically, we have created polymer structures that we call dendricolloids – they start at the microscale, but branch off from each other in a hierarchical way to create a network of nanoscale fibers,” Orlin Velev, professor of chemical and biomolecular engineering at NC State, in a press release. “This morphology creates a structure with a high surface area, which allows us to deposit DNA among the nanofibrils without sacrificing the data density that makes DNA attractive for data storage in the first place.”
“The ability to distinguish DNA information from the nanofibers it’s stored on allows us to perform many of the same functions you can do with electronic devices,” said Kevin Lin, a former Ph.D. student at NC State, in a release. “We can copy DNA information directly from the material’s surface without harming the DNA. We can also erase targeted pieces of DNA and then rewrite to the same surface, like deleting and rewriting information stored on the hard drive. It essentially allows us to conduct the full range of DNA data storage and computing functions. In addition, we found that when we deposit DNA on the dendricolloid material, the material helps to preserve the DNA.”
The device, which the researchers call a ‘primordial DNA store and compute engine,’ was able to solve simple sudoku and chess problems, with tests suggesting it could store data securely for thousands of years. [1]
Researchers from North Carolina State University, Pohang University of Science and Technology, Ulsan National Institute of Science and Technology, and University of Waterloo developed a technique for printing thin metal oxide films at room temperature, which can be used to create transparent, flexible circuits.
“Creating metal oxides that are useful for electronics has traditionally required making use of specialized equipment that is slow, expensive, and operates at high temperatures. We wanted to develop a technique to create and deposit metal oxide thin films at room temperature, essentially printing metal oxide circuits,” said Michael Dickey, professor of chemical and biomolecular engineering at NC State, in a release. “We fill the space between two glass slides with liquid metal so that a small meniscus extends beyond the ends of the slides. Think of the slides as the printer, and the liquid metal is the ink. The meniscus of liquid metal can then be brought into contact with a surface. The meniscus is covered with oxide on all sides, analogous to the thin rubber that encases a water balloon. When we move the meniscus across the surface, the metal oxide on the front and back of the meniscus sticks to the surface and peels off, like the trail left behind by a snail. As this happens, the exposed liquid on the meniscus constantly forms fresh oxide to enable continuous printing.”
The printer lays down a two-layer thin film of metal oxide that is approximately 4 nm thick. The technique was demonstrated with several liquid metals and metal alloys, with each metal altering the composition of the metal oxide film. The printed films were transparent but had metallic properties and were highly conductive, even at high temperatures. Printed on a polymer, the metal oxide created highly flexible and foldable circuits.
“Because the films have a metallic character, gold bonds to the printed oxide, which is unusual – gold normally doesn’t stick to oxides,” explained Unyong Jeong, a professor of materials science and engineering at Pohang University of Science and Technology, in a release. “When you introduce a small amount of gold to these thin films, the gold is essentially incorporated into the film. This helps prevent the conductive properties of the oxide from degrading over time.” [2]
Researchers from Monash University developed software that aims to streamline the study of materials using Scanning Tunnelling Microscopes (STMs) by automating the probe optimization and data acquisition processes.
“After countless hours spent fine-tuning the STM during my PhD, I discovered that the quality of the probe could be easily quantified by imaging imprints that it leaves behind after being poked just a few angstroms into the surface,” said Julian Ceddia, a researcher and PhD candidate at Monash, who explained in a statement that these imprints carry information about the arrangement of atoms at the tip of the scanning probe and are key to predicting how good the data will be before acquiring it. “Basically, sharper tips leave behind smaller imprints. So, Scanbot automates the process by repeatedly pressing the tip into the surface until the imprint shows that the tip is sharp enough for high-quality imaging.”
This approach avoids the challenges of using AI for tip shaping, said Benjamin Lowe, a researcher at Monash, in a statement. “Instead of training an AI on vast amounts of labeled data to recognize high-quality images, Scanbot uses simple algorithms to measure the size and symmetry of the probe apex based on the imprints it leaves.”
Beyond tip shaping, the software can automate common data acquisition techniques, such as sample surveying. [3]
[1] Lin, K.N., Volkel, K., Cao, C. et al. A primordial DNA store and compute engine. Nat. Nanotechnol. (2024). https://doi.org/10.1038/s41565-024-01771-6
[2] Minsik Kong et al., Ambient printing of native oxides for ultrathin transparent flexible circuit boards. Science 385, 731-737 (2024). https://doi.org/10.1126/science.adp3299
[3] Ceddia et al., (2024). Scanbot: An STM Automation Bot. Journal of Open Source Software, 9(99), 6028, https://doi.org/10.21105/joss.06028
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