Details

Autor(en) / Beteiligte

• Li, Minghao
• Yu, Haoxu
• Liu, Zhirui
• Gao, Ziyue
• Chen, Faze

Titel

Quantitative liquid storage by billiards‐like droplet collision on surfaces with patterned wettability

Ist Teil von

• Droplet (Print), 2024-07, Vol.3 (3), p.n/a

Ort / Verlag

Wiley

Erscheinungsjahr

2024

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• There has been significant interest in researching droplet transport behavior on composite wetting surfaces. However, current research is primarily focused on modifying individual droplets and lacks an in‐depth investigation into high‐precision droplet storage. This study introduces a “billiard ball” droplet transport and storage platform (TSP) with differentiated areas. Within this platform, the volume of droplets stored in the area reaches a consistent threshold through droplet “scrambling,” inspired by the water‐gathering behavior of spiders. The TSP involves connecting two regions of different sizes using a three‐dimensional stepped wedge angle structure. However, this connection is not seamless, leaving a 2‐mm gap between the regions. This gap is intentionally designed to enable continuous droplet transfer while preventing any static migration. Through systematic experimental and simulation analysis, we investigated the influence of superhydrophilic pattern structures and parameters on quantitative droplet storage. We established a functional relationship between the pattern area and the stored volume, and analyzed the intrinsic mechanism of droplet collision separation. This enabled us to achieve on‐demand quantitative droplet storage and autonomize the storage process. The “billiard ball” droplet transport–storage platform proposed in this study holds promising applications in the fields of biomedical and organic chemistry. Inspired by the phenomenon of spider silk water collection, this work proposes a platform design aimed at achieving quantitative storage of moving droplets (Figure a). This platform combines wettability and patterning. Interestingly, the process of droplet motion and storage resembles the impact of billiards, providing a novel approach for integrating reaction and storage in practical applications. To ensure constant droplet storage volume, we suppress the “passive migration” behavior of droplets and design the connecting wedges as a three‐dimensional gradient structure to compensate for velocity loss. The quantitative storage of droplets is achieved through the uneven contention among circular domains, which correlates with the storage threshold of droplets (Figure b). As depicted in Figure c, when characterizing droplet separation degree by adhesion time, small supplemental droplets are transitionally attracted by van der Waals forces but still maintain prolonged contact with the connecting wedges. Beyond a droplet volume of 70 µL, this transition is facilitated through interdomain competition. The research findings demonstrate that the platform can achieve customized storage volumes not limited to a single droplet volume. Finally, we design an automated platform that autonomously accomplishes droplet collection, transport, and quantitative storage (Figure d).