In a groundbreaking development, scientists from the Indian Institute of Science (IISc) have unveiled a novel method for encapsulating liquid droplets with far-reaching implications for various fields. Published in Nature Communications, the study introduces a technique harnessing the capillary effect to create composite shells with tunable thickness, allowing the encapsulation of droplets of different sizes.
Lead researcher Rutvik Lathia, a PhD student at the Centre for Nano Science and Engineering (CeNSE), IISc, underscores the significance of droplets in diverse applications. Whether in microreactors for creating distinct reaction environments, drug delivery systems targeting specific tissues, crystallization studies controlling crystal growth, or cell culture platforms optimizing cell viability, droplets play a pivotal role.
However, challenges such as vulnerability to contamination, surface dependence, and rapid evaporation have impeded the seamless utilization of droplets. To overcome these hurdles, Prosenjit Sen, Associate Professor at CeNSE, and his team developed a capillary force-assisted cloaking method.
The process involves coating droplets with hydrophobic and oil-loving beads, transforming them into “Liquid Marbles” (LM). Placing these LM on oil-infused surfaces triggers capillary forces, causing oil to rise into tiny pores between beads. This mechanism forms a stable liquid film around the droplet, effectively encapsulating it. By using wax instead of oil and adjusting the temperature, the team achieved a solid shell.
This encapsulation significantly reduces droplet evaporation rates, extending their lifetime by up to 200 times. The team demonstrated remarkable flexibility by adjusting shell thickness from 5 μm to 200 μm, accommodating droplets with volumes ranging from 14 nL to 200 μL.
Associate Professor Sen emphasizes the versatility of this method, noting its application in chemistry, biology, and materials science. The researchers successfully employed coated droplets to grow single crystals and enhance biological applications like 3D cell culture and yeast cell growth in the lab.
Further he expresses his plans to explore alternative materials for capsules, aiming to enhance tunability further, particularly with polymer-based capsules. This groundbreaking encapsulation technique opens new avenues for precision control in droplet-related applications, marking a significant advancement in scientific research.
