Nanowerk 报道: “原子级机器人操作：单原子链应力感知"
A silver single-atom chain demonstrates atomic-scale strain sensing and piezoresistive effects, advancing nanotechnology and nanoscale sensing capabilities.
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| (Nanowerk Spotlight) At the scale of individual atoms, materials behave in ways that defy everyday intuition. Stretch a metal wire by a few micrometers and its resistance changes only slightly. Stretch a chain of just a few atoms by a fraction of a nanometer, and the flow of electrons can change dramatically, shifting a structure from highly conductive to nearly insulating. Yet directly observing how atomic-scale strain transforms electronic transport has remained out of reach. Microscopes could show atoms, and electrical measurements could track currents, but not at the speed and precision needed to capture both at once. The critical link — seeing and measuring how a single atom chain stretches, strains, and conducts in real time — was missing. |
| Now, researchers at the City University of Hong Kong have bridged that gap. Using an exceptionally stable chain of silver atoms, they have demonstrated that atomic-scale strain sensing is not only possible, but that the resulting changes in resistance are far larger than anything seen at the macroscopic level. By combining direct mechanical manipulation with real-time electrical measurements inside a transmission electron microscope, they have captured a complete, atom-by-atom picture of how strain controls electronic transport at the most fundamental scale. |
| Their study, published in Advanced Science ("Atomic-Level Strain Sensing and Piezoresistance Effect in a 1D Single-Atom Chain"), focuses on the construction and testing of a one-dimensional silver atom chain, fabricated in situ under a dual spherical aberration-corrected transmission electron microscope. Using a nanomanipulator capable of sub-angstrom precision, the team exfoliated atomically clean surfaces and formed stable atomic chains by bringing two silver crystals into contact under carefully controlled conditions. By applying a low bias voltage, they encouraged silver atoms to diffuse and bond across the interface, forming a suspended chain just one atom wide. |