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Unique among traditional fillers, the metallically conductive liquid metal galinstan has emerged as an inherently deformable alternative for polymer composites. Galinstan exhibits high electrical conductivity with liquid-like flow, which sets it apart from the solid metals and ceramics typically used to impart electrical behavior to polymers. Upon exposure to atmospheric oxygen, galinstan forms a solid oxide shell that adds mechanical complexity when blended with polymers to create liquid metal polymer composites (LMPCs). This study investigates the mechanical behavior of LMPCs under tension, compression, and torsion as a function of LM droplet size and loading. Experimental analysis and computational modeling reveal distinct behaviors in LMPCs depending on the applied force and droplet characteristics that do not follow the classic composite models like Eshelby theory or more recent, updated versions thereof. Despite the large modulus difference between the LM and oxide shell, focusing exclusively on individual droplet mechanics overlooks the importance of surface energy dynamics within the system. By incorporating interfacial energy into a novel model, the origins of the LMPC mechanical response under deformation were illustrated. Our findings contribute to a broader understanding of composite materials with implications for soft robotics, where material response to various deformations is crucial for functionality. 

Smart emulsions are both versatile additives to smart materials and functional smart materials themselves, acting as active components and structural elements driving innovative development. Emulsions offer versatility, ease of manipulation, and stability to smart materials. This review explores the multifaceted roles of emulsions, examining their formulation methods, applications, and role as building blocks in smart materials. The significance of emulsions in smart materials is discussed for applications such as drug delivery and adaptive coatings, as well as their role in stimuli‐responsive colloidal systems and nanocomposites. The smart emulsions reviewed encompass all manner of material types, including fluid and solid/polymerized smart materials. These include both emulsions with dynamic properties and emulsions used in the process of synthesizing other materials. Smart emulsions are categorized by application into shape memory, self‐healing, biological, and stimuli‐responsive, with analysis of formulation methods, metrics, and methods of final incorporation. Smart emulsions can be found initially as fluid systems and some react into solid polymers, tailored to meet functional needs. A comparative analysis reveals emerging trends such as coupling coating self‐healing/corrosion inhibition and use of waterborne polyurethanes. The discussion of smart emulsions concludes by outlining challenges and future directions for leveraging smart emulsions. 

A novel method achieved non-conductive LMPCs with uniform dispersion revealing unique galinstan concentration relationships and insights on homogeneity, dielectric strength, and sensing behavior to advance soft, deformable electronics research. 

Gallium-based liquid metals are unique in their deformably, conductive nature and the oxide that grows natively on their surface. The oxide of galinstan, gallium–indium–tin, is composed of Ga/In/Sn oxides known for their semiconducting properties. The native galinstan oxide, however, is amorphous and improving electrical properties is understudied. In this work, annealing, a method for improving conductivity and hardness in metals and ceramics, is studied to control galinstan oxide crystallinity, modulus, and resistivity. It was found that while annealing increases crystallinity and grain size, local composition and thickness must also be considered when analyzing galinstan oxide electrical and mechanical properties.