Stretchable Systems

Stretchable electronics is one of the transformative pillars of future flexible electronics. As a result, the research on new passive and active materials, novel designs, and engineering approaches has attracted significant interest. Recent studies have highlighted the importance of new approaches that enable the integration of high-performance materials, including, organic and inorganic compounds, carbon-based and layered materials, and composites to serve as conductors, semiconductors or insulators, with the ability to accommodate electronics on stretchable substrates. This Element presents a discussion about the strategies that have been developed for obtaining stretchable systems, with a focus on various stretchable geometries to achieve strain invariant electrical response, and summarises the recent advances in terms of material research, various integration techniques of high-performance electronics. In addition, some of the applications, challenges and opportunities associated with the development of stretchable electronics are discussed.

Autowave Mechanics of Plastic Flow

The notions of plastic flow localization are reviewed here. It have been shown that each type of localized plasticity pattern corresponds to a given stage of deformation hardening. In the course of plastic flow development a changeover in the types of localization patterns occurs. The types of localization patterns are limited to a total of four pattern types. A correspondence has been set up between the emergent localization pattern and the respective flow stage. It is found that the localization patterns are manifestations of the autowave nature of plastic flow localization process, with each pattern type corresponding to a definite type of autowave. Propagation velocity, dispersion and grain size dependence of wavelength have been determined experimentally for the phase autowave. An elastic-plastic strain invariant has also been introduced to relate the elastic and plastic properties of the deforming medium. It is found that the autowave’s characteristics follow directly from the latter invariant. A hypothetic quasi-particle has been introduced which correlates with the localized plasticity autowave; the probable properties of the quasi-particle have been estimated. Taking the quasi-particle approach, the characteristics of the plastic flow localization process are considered herein.

Strain-invariant conductance in an elastomeric nanocomposite mesh conductor for stretchable electronics

A conductive serpentine mesh of elastomeric nanocomposite is created by selective laser ablation for stretchable electronics, which exhibits strain-invariant conductance, mechanical compliance, and excellent breathability.

Autowave Physics of Material Plasticity

The notions of plastic flow localization are outlined in the paper. It is shown that each type of localized plasticity pattern corresponds to a definite stage of deformation hardening. In the course of plastic flow development, a changeover in the types of localization patterns occurs. The types of localization patterns are limited in number: four pattern types are all that can be expected. A correspondence was set up between the emergent localization pattern and the respective flow stage. It is found that the localization patterns are manifestations of the autowave nature of plastic flow localization process, with each pattern type corresponding to a definite mode of autowave. In the course of plastic flow development, the following modes of autowaves will form in the following sequence: switching autowave → phase autowave → stationary dissipative structure → collapse of the autowave. Of particular interest are the phase autowave and the respective pattern observed. Propagation velocity, dispersion, and grain size dependence of wavelength were determined experimentally for the phase autowave. An elastic-plastic strain invariant was also introduced to relate the elastic and plastic properties of the deforming medium. It is found that the autowave characteristics follow directly from this invariant.