Extending Lifetime of Water Droplets Using Mirror‐Nanoporous Surfaces

Abstract

to integrate versatile platforms, the low reagent/sample consumption, and the high throughput that can be achieved via automation. [5] To perform assays on such small liquid volumes (i.e., microliter range), especially in many bioapplications that require operation at physiological temperature (37 °C), it is critical to reduce the evaporation rate of the droplets to expand their lifetime. Physiological temperature is indeed necessary in the operation of a wide range of biochemical assays, such as in most cell culture techniques [6] (from single [7] to 3D cell culture [8]) and several enzymebased analysis. [9] To date, methods to slow down droplet evaporation generally use high-humidity chambers or put the droplets under an oxygen-permeable biocompatible oil barrier.

Droplet evaporation in finite-size systems: Theoretical analysis and mesoscopic modeling

“…Deviations from the classical D 2 -Law have been frequently observed, especially in droplet evaporation experiments in confined space [13] or in numerical simulations, e.g., evaporation of nanosize droplets and/or under supercritical conditions [14,15]. Among others, one reason accounting for the deviation is that the classical D 2 -Law is established for large open systems (L/D 0 1, L is the system size), which is not always the case in laboratory conditions, while simulations are inevitably limited to finite-size systems.…”

“…As discussed above, the classical D 2 -Law is established for large 3D systems, while a finite size and/or 2D system is encountered in many situations, which has not yet been systematically investigated. In experiments, examples of finite-size systems are the evaporation of a single droplet in microfluidic systems [13,31] or a dense collection of millimetric/micrometric droplets in a macroscale combustion chamber [32]. From the numerical simulation point of view, the system size is always limited by the computational cost [14], and 2D simulations are often considered for preliminary studies or model validation [29].…”

Two-Dimensional Confinement for Generating Thin Single Crystals for Time-Resolved Electron Diffraction and Spectroscopy: An Intramolecular Proton Transfer Study

“…where 𝛾 is the interfacial tension, 𝜈 is the molar volume of solute, k is the Boltzmann constant, and 𝑇 is temperature (°K). 28 Evaporation of solvent in the confined area is slower than in the open areas, as Berli et al showed with sessile and confined water droplets, 29 which induces slower increase of 𝑆. At a certain time during evaporation leading to the nucleation step, the supersaturation is lower in the confined space than in the open space; it means that the nucleation barrier is higher in the confined area than in open areas at the same time.…”

Two-dimensional confinement for generating thin single crystals for applications in time-resolved electron diffraction and spectroscopy: an intramolecular proton transfer study

“…Even after the solution in the confined area is exposed to air, the much smaller surface to volume ratio of the solution in the confined area than that in open area ensures longer evaporation time. 29 Crystal growth is a kinetic process governed by transport of solute particles, surface diffusion, and equilibrium between adsorption and desorption. Those motions of solute particles in the confined space during evaporation are more restrained, which gives more stable crystal growth rates.…”