The unique elastic bendability is the foundation for the widespread application of inorganic flexible electronics. Recently, Prof. Su Yewang of Institute of Mechanics Chinese Academy of Sciences, proposed a novel overbend strategy that can enhance the elastic bendability of flexible electronics to twice or more times through simple operation., The international academic journal 《Science Advances》 published this achievement on Aug 30.

Currently, thousands of studies have adopted bendable structures through mechanical design, most of them focus on two types of structures with similar mechanical principles: single-layer metal foil and multi-layer stacks. However, strategies to enhance the elastic bendability of these two structures have primarily centred on reducing structural thickness.

Prof. Su Yewang proposed an overbend strategy, with ideal elastoplastic materials as an example, applying the deformation exceeding the designed elastic flexibility can double the elastic flexibility. The core mechanism leverages the evolution of the constitutive relationship to increase the elastic strain range at critical sections by two times.

This strategy proves effective not only for ideal elastoplastic materials but also for plastic hardening materials. For materials with the kinematic hardening constitutive relation, the strategy doubles the designed elastic bendability. For materials with the mixed hardening/isotropic hardening constitutive relation, it enhances the elastic bendability by more than twice.

Furthermore, this strategy remains effective for geometric interconnects bonded to soft substrates—common in flexible electronics. For instance, it can enhance the elastic bendability of serpentine, zigzag, and fractal interconnects by twofold or more.

In practical applications, the overbend strategy can be extended into a universal overload strategy applicable to various complex deformation patterns, demonstrating significant application potential.

Original link: https://www.science.org/doi/10.1126/sciadv.adv6631

Contact：

ZHANG Ziao

Institute of Mechanics Chinese Academy of Sciences

Tel：86-010-82543676

E-mail：ziaozhang@imech.ac.cn

Web：http://www.imech.cas.cn/