Description
Liquid marbles are droplets encapsulated by a layer of hydrophobic or superhydrophobic particles which provide a versatile platform for contactless liquid handling in microfluidic systems. Their ability to minimize solid–liquid interactions makes them attractive for applications ranging from microreactors to sensing and actuation. In this work, we report the fabrication of stable liquid marbles using lithium niobate (LiNbO₃) powder rendered superhydrophobic via polydimethylsiloxane (PDMS) surface modification. While lithium niobate is a well-established functional material with piezoelectric, ferroelectric, and electro-optic properties, its intrinsic hydrophilicity has previously limited its use in liquid marble systems.
Superhydrophobic lithium niobate particles were prepared by coating LiNbO₃ powder with PDMS, resulting in a low-surface-energy layer on the particle surface. The PDMS-modified powder exhibited strong water repellency and readily adhered to the liquid–air interface. Liquid marbles were formed by gently rolling aqueous droplets over a bed of the modified lithium niobate powder, leading to uniform particle coverage and complete encapsulation of the liquid core. The resulting liquid marbles demonstrated excellent non-wetting behavior and mechanical stability. The droplets retained their spherical shape and structural integrity during handling, rolling, and translational motion on solid substrates, with no observable liquid leakage or substrate wetting. The robustness of the particle shell indicates effective PDMS-mediated hydrophobization and strong particle attachment at the interface, both of which are critical for microfluidic manipulation.
The integration of lithium niobate into liquid marbles introduces a new class of functional droplets with the potential for field-responsive actuation and sensing. Owing to the intrinsic electro-mechanical and optical properties of lithium niobate, these liquid marbles offer opportunities for externally addressable microfluidic elements, such as electrically or mechanically stimulated droplets and optically active microreactors. This work expands the material palette for liquid marble microfluidics and provides a foundation for multifunctional droplet systems in next-generation microfluidic architectures.