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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. 

Abstract Skin‐like robust materials with prominent sensing performance have potential applications in flexible bioelectronics. However, it remains challenging to achieve mutually exclusive properties simultaneously including low interfacial impedance, high stretchability, sensitivity, and electrical resilience. Herein, a material and structure design concept of mixed ion‐electron conduction and mechanical interlocking structure is adopted to fabricate high‐performance mechanical‐bioelectrical dual‐modal composites with large stretchability, excellent mechanoelectrical stability, low interfacial impedance, and good biocompatibility. Flower‐like conductive metal‐organic frameworks (cMOFs) with enhanced conductivity through the overlapped level of metal‐ligand orbital are assembled, which bridge carbon nanotubes (denoted as cMOFs‐b‐CNTs). Then, precursor of poly(styrene‐block‐butadiene‐block‐styrene)/ionic liquid penetrates the pores and cavities in cMOFs‐b‐CNTs‐based network fabricated via filtration process, creating a semi‐embedded structure via mechanical interlocking. Thus, the mixed ion‐electron conduction and semi‐embedded structure endow the as‐prepared composites with a low interfacial impedance (51.60/28.90 kΩ at 10/100 Hz), wide sensing range (473%), high sensitivity (2195.29), rapid response/recovery time (60/85 ms), low limit of detection (0.05%), and excellent durability (>5000 cycles to 50% strain). Demonstrations of multifunctional mechanical‐bioelectrical dual‐modal sensors for in vivo/vitro monitoring physiological motions, electrophysiological activities, and urinary bladder activities validate the possibility for practical uses in biomedical research areas. This concept creates opportunities for the construction of durable skin‐like sensing materials. 

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. 

Electrostatic capacitors are foundational components of advanced electronics and high-power electrical systems owing to their ultrafast charging-discharging capability. Ferroelectric materials offer high maximum polarization, but high remnant polarization has hindered their effective deployment in energy storage applications. Previous methodologies have encountered problems because of the deteriorated crystallinity of the ferroelectric materials. We introduce an approach to control the relaxation time using two-dimensional (2D) materials while minimizing energy loss by using 2D/3D/2D heterostructures and preserving the crystallinity of ferroelectric 3D materials. Using this approach, we were able to achieve an energy density of 191.7 joules per cubic centimeter with an efficiency greater than 90%. This precise control over relaxation time holds promise for a wide array of applications and has the potential to accelerate the development of highly efficient energy storage systems.