Researchers have found a way to make the hardest naturally occurring substance in the world flexible, creating nanoscale "needles" of diamonds that can bend. The development could hold implications for bioimaging and biosensing, optomechanical devices, ultra-strength nanostructures and more. Besides their sparkling beauty, diamonds are desirable for a wide range of applications because of their remarkable hardness and durability. However, any attempt to deform diamonds usually results in brittle fractures. Here, Amit Banerjee and colleagues discovered a way to make this notoriously unyielding material "give" a little. They took thin films of artificial diamonds and etched from the material tiny needles, just 300 nanometers in length. Prodding the thin slivers of diamond revealed that they can withstand strains up to 9%, approaching the theoretical limit of diamond flexibility. The authors report that single-crystal diamond "nanoneedles" generally achieve a much higher local maximum tensile strain than the polycrystalline ones. Javier LLorca provides more context in a related Perspective, noting, "Exploration of the effect of very large elastic strains (up to 10%) on the properties of crystalline solids may lead to the discovery of new or unexpected behaviors."
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Science