Enhancing the Stability and the Scalability of Tree‐Mimicking Dewatering Devices by Employing Hygroscopic Cellulose

ABSTRACT Passive fluid transfer and dewatering at a large scale by evaporation‐induced capillary pumping (i.e., artificial trees) hinge on water conduit robustness to embolism under negative pressure and on the amplification of evaporative flows. We propose a hygroscopic cellulose‐based tree‐mimicking device for stable and scalable dewatering. First, the remarkable capacity of the hygroscopic cellulose as the stem material in maintaining its hydration is demonstrated in dynamic vapor sorption and deuterium oxide‐normal water (D ₂ O‐H ₂ O) replacement tests. Subsequently, molecular dynamics simulations show that the surface chemistry of the hygroscopic cellulose effectively deters the onset of embolism, as compared to representative hydrophobic and hydrophilic surfaces. Next, in dewatering experiments, we find that the cellulose stem supersaturates the artificial leaf, which results in ∼50% higher evaporation rates compared to its equilibrium state. Finally, the evaporative flux at the leaf is shown to be nearly independent of the root area, proving the potential to amplify the flux via increasing the leaf area and the scalability of tree‐mimicking devices for dewatering applications.