Sbarra Samantha, Waquier Louis, Suffit Stephan, Lemaître Aristide, Favero Ivan
Matériaux et Phénomènes Quantiques, Université Paris Cité, CNRS, UMR 7162, 75013, Paris, France.
Centre de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, UMR 9001, 91120, Palaiseau, France.
Nat Commun. 2022 Oct 29;13(1):6462. doi: 10.1038/s41467-022-34219-3.
Tracking the evolution of an individual nanodroplet of liquid in real-time remains an outstanding challenge. Here a miniature optomechanical resonator detects a single nanodroplet landing on a surface and measures its subsequent evaporation down to a volume of twenty attoliters. The ultra-high mechanical frequency and sensitivity of the device enable a time resolution below the millisecond, sufficient to resolve the fast evaporation dynamics under ambient conditions. Using the device dual optical and mechanical capability, we determine the evaporation in the first ten milliseconds to occur at constant contact radius with a dynamics ruled by the mere Kelvin effect, producing evaporation despite a saturated surrounding gas. Over the following hundred of milliseconds, the droplet further shrinks while being accompanied by the spreading of an underlying puddle. In the final steady-state after evaporation, an extended thin liquid film is stabilized on the surface. Our optomechanical technique opens the unique possibility of monitoring all these stages in real-time.
实时追踪单个液体纳米液滴的演变仍然是一个重大挑战。在此，一个微型光机械谐振器可检测落在表面上的单个纳米液滴，并测量其随后蒸发至二十阿托升体积的过程。该设备的超高机械频率和灵敏度实现了低于毫秒级的时间分辨率，足以解析环境条件下的快速蒸发动力学。利用该设备的光学和机械双重能力，我们确定在前十毫秒内蒸发以恒定接触半径发生，其动力学仅受开尔文效应支配，即使周围气体饱和也会产生蒸发。在接下来的数百毫秒内，液滴进一步收缩，同时伴随着下层水洼的扩散。在蒸发后的最终稳态中，表面形成了一层扩展的薄液膜并得以稳定。我们的光机械技术开启了实时监测所有这些阶段的独特可能性。
