A unified analysis of a micro-beam,droplet and CNT ring adhered on a substrate:Calculation of variation with movable boundaries

In this study, we developed a general method to analytically tackle a kind of movable boundary problem from the viewpoint of energy variation. Having grouped the adhesion of a micro-beam, droplet and carbon nanotube （CNT） ring on a substrate into one framework, we used the developed line of reasoning to investigate the adhesion behaviors of these systems. Based upon the derived governing equations and transversality conditions, explicit solutions involving the critical parameters and morphologies for the three systems are successfully obtained, and then the parameter analogies and common characteristics of them are thor- oughly investigated. The presented method has been verified via the concept of energy release rate in fracture mechanics. Our analyses provide a new approach for exploring the mechanism of different systems with similarities as well as for understanding the unity of nature. The analysis results may be beneficial for the design of nano-structured materi- als, and hold potential for enhancing their mechanical, chemical, optical and electronic properties.

Large-area, kirigami topology structure-induced highly stretchable and flexible interconnects: Directly printing preparation and mechanic mechanism

Integrating the topology design and printing method offers a promising methodology to realize large stretchability for interconnects.Herein,eco-friendly and waterbased Ag nanowires(NWs)inks were formulated and used for screen-printing highly stretchable and flexible interconnects on a large area(more than 335 mm x 175 mm).The stretchability of the interconnects was realized by introducing kirigami topology structures.The topology designed models were established to simulate the influence of kirigami patterns on wire compliance and to estimate the maximum stretchability via finite element analysis(FEA).The mechanic mechanism results demonstrate that an increase of the wave numbers results in larger stretchability,and the rectangular type of wave shows better stretchability than the zigzag and sine structures.Comparatively,the electrical and mechanical properties of the interconnects were measured and analyzed,and the experimental results were consistent with FEA.The electric conductivity of the interconnects is stable at^10,427 S cm-1 even after 1000 cycles of 15.83 mm radius bending,280%stretching and 200%twisting-stretching deformation,demonstrating outstanding mechanical reliability of the interconnects.The topology designed interconnects have been applied in stretchable flexible light-emitting diode,indicating their broad application prospects in next-generation stretchable electronics.

Mechanics and Wave Propagation Characterization of Chiral S-Shaped Auxetic Metastructure

Auxetic metastructures have attracted tremendous attention because of their robust multifunctional properties and promising potential industrial applications.This paper studies the in-plane mechanical behaviors of a chiral S-shaped metastructure subjected to tensile loading in both X-direction and Y-direction and wave propagation properties using the finite element(FE)method.The relationships between structural parameters and elastic behaviors are also discussed.The results indicate that the orientation of chiral S-shaped metastructure under tensile loading in the X-direction exhibits higher auxeticity and stiffness.Then,the band structures and the edge modes of each band gap of the chiral S-shaped metastructure are explored,and the relations between band gap properties and structural parameters are also systematically analyzed.Moreover,we explore the wave mitigation of the chiral S-shaped metastructures by regulating the structural parameters.Finally,the transmission properties of the finite chiral S-shaped periodic metastructures are studied to confirm the results of band gap simulation.This study promotes the engineering application of vibration isolation of chiral structures based on the band gap theory.