Printable Self-Activated Liquid Metal Stretchable Conductors from Polyvinylpyrrolidone-Functionalized Eutectic Gallium Indium Composites

Stretchable electronic circuits are critical in a variety of next-generation electronics applications, including soft robots, wearable technologies, and biomedical applications. To date, printable composite conductors comprising various types of conductive fillers have been suggested to achieve high electrical conductance and excellent stretchability. Among them, liquid metal particles have been considered as a viable candidate filler that can meet the necessary prerequisites. However, a mechanical activation process is needed to generate interconnected liquid channels inside elastomeric polymers. In this study, we have developed a chemical strategy of surface-functionalizing liquid metal particles to eliminate the necessity of additional mechanical activation processes. We found that the characteristic conformations of the polyvinylpyrrolidone surrounding eutectic gallium indium particles are highly dependent on the molecular weight of polyvinylpyrrolidone. By virtue of the specific chemical roles of polyvinylpyrrolidone, the as-printed composite layers are highly conductive and stretchable, exhibiting an electrical conductivity approaching 8372 S/cm at 100% strain and an invariant resistance change of 0.92 even at 75% strain after a 60,000 cycle test. The results demonstrate that the self-activated liquid metal-based composite conductors are applicable to traditional stretchable electronics, healable stretchable electronics, and shape-morphable applications

Regional Control of Multistimuli-Responsive Structural Color-Switching Surfaces by a Micropatterned DNA-Hydrogel Assembly

Structural colors have advantages compared with chemical pigments or dyes, such as iridescence, tunability, and unfading. Many studies have focused on developing the ability to switch ON/OFF the structural color; however, they often suffer from a simple and single stimulus, remaining structural colors, and target selectivity. Herein, we present regionally controlled multistimuli-responsive structural color switching surfaces. The key part is the utilization of a micropatterned DNA-hydrogel assembly on a single substrate. Each hydrogel network contains a unique type of stimuli-responsive DNA motifs as an additional cross-linker to exhibit swelling/deswelling via stimuli-responsive DNA interactions. The approach enables overcoming the existing limitations and selectively programming the DNA-hydrogel to a decrypted state (ON) and an encrypted state (OFF) in response to multiple stimuli. Furthermore, the transitions are reversible, providing cyclability. We envision the potential of our method for diverse applications, such as sensors or anticounterfeiting, requiring multistimuli-responsive structural color switching surfaces

Printable Self-Activated Liquid Metal Stretchable Conductors from Polyvinylpyrrolidone-Functionalized Eutectic Gallium Indium Composites

Stretchable electronic circuits are critical in a variety of next-generation electronics applications, including soft robots, wearable technologies, and biomedical applications. To date, printable composite conductors comprising various types of conductive fillers have been suggested to achieve high electrical conductance and excellent stretchability. Among them, liquid metal particles have been considered as a viable candidate filler that can meet the necessary prerequisites. However, a mechanical activation process is needed to generate interconnected liquid channels inside elastomeric polymers. In this study, we have developed a chemical strategy of surface-functionalizing liquid metal particles to eliminate the necessity of additional mechanical activation processes. We found that the characteristic conformations of the polyvinylpyrrolidone surrounding eutectic gallium indium particles are highly dependent on the molecular weight of polyvinylpyrrolidone. By virtue of the specific chemical roles of polyvinylpyrrolidone, the as-printed composite layers are highly conductive and stretchable, exhibiting an electrical conductivity approaching 8372 S/cm at 100% strain and an invariant resistance change of 0.92 even at 75% strain after a 60,000 cycle test. The results demonstrate that the self-activated liquid metal-based composite conductors are applicable to traditional stretchable electronics, healable stretchable electronics, and shape-morphable applications

Printable Self-Activated Liquid Metal Stretchable Conductors from Polyvinylpyrrolidone-Functionalized Eutectic Gallium Indium Composites

Stretchable electronic circuits are critical in a variety of next-generation electronics applications, including soft robots, wearable technologies, and biomedical applications. To date, printable composite conductors comprising various types of conductive fillers have been suggested to achieve high electrical conductance and excellent stretchability. Among them, liquid metal particles have been considered as a viable candidate filler that can meet the necessary prerequisites. However, a mechanical activation process is needed to generate interconnected liquid channels inside elastomeric polymers. In this study, we have developed a chemical strategy of surface-functionalizing liquid metal particles to eliminate the necessity of additional mechanical activation processes. We found that the characteristic conformations of the polyvinylpyrrolidone surrounding eutectic gallium indium particles are highly dependent on the molecular weight of polyvinylpyrrolidone. By virtue of the specific chemical roles of polyvinylpyrrolidone, the as-printed composite layers are highly conductive and stretchable, exhibiting an electrical conductivity approaching 8372 S/cm at 100% strain and an invariant resistance change of 0.92 even at 75% strain after a 60,000 cycle test. The results demonstrate that the self-activated liquid metal-based composite conductors are applicable to traditional stretchable electronics, healable stretchable electronics, and shape-morphable applications

Printable Self-Activated Liquid Metal Stretchable Conductors from Polyvinylpyrrolidone-Functionalized Eutectic Gallium Indium Composites

Stretchable electronic circuits are critical in a variety of next-generation electronics applications, including soft robots, wearable technologies, and biomedical applications. To date, printable composite conductors comprising various types of conductive fillers have been suggested to achieve high electrical conductance and excellent stretchability. Among them, liquid metal particles have been considered as a viable candidate filler that can meet the necessary prerequisites. However, a mechanical activation process is needed to generate interconnected liquid channels inside elastomeric polymers. In this study, we have developed a chemical strategy of surface-functionalizing liquid metal particles to eliminate the necessity of additional mechanical activation processes. We found that the characteristic conformations of the polyvinylpyrrolidone surrounding eutectic gallium indium particles are highly dependent on the molecular weight of polyvinylpyrrolidone. By virtue of the specific chemical roles of polyvinylpyrrolidone, the as-printed composite layers are highly conductive and stretchable, exhibiting an electrical conductivity approaching 8372 S/cm at 100% strain and an invariant resistance change of 0.92 even at 75% strain after a 60,000 cycle test. The results demonstrate that the self-activated liquid metal-based composite conductors are applicable to traditional stretchable electronics, healable stretchable electronics, and shape-morphable applications

Printable Self-Activated Liquid Metal Stretchable Conductors from Polyvinylpyrrolidone-Functionalized Eutectic Gallium Indium Composites

Stretchable electronic circuits are critical in a variety of next-generation electronics applications, including soft robots, wearable technologies, and biomedical applications. To date, printable composite conductors comprising various types of conductive fillers have been suggested to achieve high electrical conductance and excellent stretchability. Among them, liquid metal particles have been considered as a viable candidate filler that can meet the necessary prerequisites. However, a mechanical activation process is needed to generate interconnected liquid channels inside elastomeric polymers. In this study, we have developed a chemical strategy of surface-functionalizing liquid metal particles to eliminate the necessity of additional mechanical activation processes. We found that the characteristic conformations of the polyvinylpyrrolidone surrounding eutectic gallium indium particles are highly dependent on the molecular weight of polyvinylpyrrolidone. By virtue of the specific chemical roles of polyvinylpyrrolidone, the as-printed composite layers are highly conductive and stretchable, exhibiting an electrical conductivity approaching 8372 S/cm at 100% strain and an invariant resistance change of 0.92 even at 75% strain after a 60,000 cycle test. The results demonstrate that the self-activated liquid metal-based composite conductors are applicable to traditional stretchable electronics, healable stretchable electronics, and shape-morphable applications

Printable Self-Activated Liquid Metal Stretchable Conductors from Polyvinylpyrrolidone-Functionalized Eutectic Gallium Indium Composites

Stretchable electronic circuits are critical in a variety of next-generation electronics applications, including soft robots, wearable technologies, and biomedical applications. To date, printable composite conductors comprising various types of conductive fillers have been suggested to achieve high electrical conductance and excellent stretchability. Among them, liquid metal particles have been considered as a viable candidate filler that can meet the necessary prerequisites. However, a mechanical activation process is needed to generate interconnected liquid channels inside elastomeric polymers. In this study, we have developed a chemical strategy of surface-functionalizing liquid metal particles to eliminate the necessity of additional mechanical activation processes. We found that the characteristic conformations of the polyvinylpyrrolidone surrounding eutectic gallium indium particles are highly dependent on the molecular weight of polyvinylpyrrolidone. By virtue of the specific chemical roles of polyvinylpyrrolidone, the as-printed composite layers are highly conductive and stretchable, exhibiting an electrical conductivity approaching 8372 S/cm at 100% strain and an invariant resistance change of 0.92 even at 75% strain after a 60,000 cycle test. The results demonstrate that the self-activated liquid metal-based composite conductors are applicable to traditional stretchable electronics, healable stretchable electronics, and shape-morphable applications