Directional and Tunable Evaporation of Liquid Marbles via an Asymmetric and Reconfigurable Architecture Synergizing Permeable‐Impermeable Domains

Particle-armored liquid droplets (liquid marbles) have emerged as a multifunctional microfluidic system for sensing, active-material delivery, biosynthesis, and analysis, owing to their ease of fabrication, versatility, nonstickiness, and gas permeability. While the porous characteristic of the liquid marbles is essential for mediating interactions with the surrounding environment, it inevitably leads to evaporation-driven mass loss, limiting their lifetime, stability, and effective utilization. Furthermore, evaporation dynamics and structural integrity of the marbles are subject to substrate-dependent effects that modulate thermal and vapor transport through the particulate shell. We address these challenges by introducing a hybrid interfacial design: a dual-faced liquid marble comprising permeable (particulate) and impermeable domains, namely, a hybrid Janus liquid marble (hJLM), with a tunable structural profile. The asymmetric structure of the hJLMs enables tunability and substrate-independent directional control over the evaporation of encapsulated liquid. The hJLMs exhibit greater resistance to operational conditions, including substrate type (solid or liquid), temperature, and external compression pressure, thereby enhancing their lifespan and mechanical integrity. We demonstrate the versatility and reusability of the hJLMs by reconfiguring them with different liquid-particle combinations. We believe that the unique structure and enhanced functionality of the hJLMs could improve the sustainability and efficiency of droplet-based platforms.