High-Resolution Patterning of Magnetic Liquid-Metal Nanohybrid Particles for Flexible Electronics

The development of highly flexible and stretchable electronics has driven considerable interest in liquid-metal (LM) materials, renowned for their exceptional mechanical and electrical properties. However, fully realizing LM's potential has been hindered by difficulties in achieving high-resolution patterning and large-scale integration, limiting their control and practical applications. To address these challenges, we modified the surface of the LM oxide to introduce sub-10 nm nano-magnets, forming magnetic LM nanohybrid particles (MagLPs). By doping the native oxide layer of gallium-based LMs with hydrogen and applying acoustic fields, we achieved precise coating of superparamagnetic nanoparticles (MNPs) on LM cores. This scalable method enables the production of uniform, sub-micron MagLPs with customizable magnetic properties. Building on the unique magnetic properties of MagLPs, we developed a versatile LM patterning platform using magnetic templates, which significantly outperforms conventional methods for magnetic LM hybrid patterning. Our approach enables fine, high-resolution patterns with sub-micron precision on various substrates, including stretchable elastomers, through room-temperature processing under ambient conditions. Additionally, the integration of high-frequency alternating magnetic fields (AMFs) facilitates non-contact activation and interconnection of MagLP circuits, supporting rapid, large-area, and wafer-scale production of complex patterns. To demonstrate the potential of this method, we fabricated a soft, stretchable multielectrode array (MEA) device capable of direct HL-1 cell subculturing. The device showed excellent performance, recording significant signal spikes after four days. This work establishes a robust platform for advanced LM-based materials and devices, paving the way for innovations in flexible electronics, soft robotics, and biomedical engineering.