Bioinspired Reversible Adhesive with High Strength for Wearable Electronics under Diverse Environments.

Wearable electronics serve as critical tools for human health monitoring and equipment operation assessment. A fundamental prerequisite for their stable performance is the ability to attach flexibly and reliably to the surfaces of human bodies or equipment. However, existing adhesion methods for wearable devices face substantial challenges in simultaneously achieving high-strength reversible bonding and environmental adaptability across diverse conditions, hindering the practical applications in complex and variable environments. Here, inspired by the excellent adhesion behaviors of geckos and octopuses, we designed a dual bioinspired adhesive microstructure consisting of an annular stalk, a microdome, and an annular tip. The large-area precise formation of this complex 3-dimensional microstructure is achieved via simple imprinting and photolithography. The fabricated adhesive demonstrated reversible and superior normal adhesion in complex environments including vacuum (120 kPa), dry (201 kPa), moist (173 kPa), and underwater (165 kPa). In situ observations of the contact splitting reveal that its extraordinary performance derives from the unique crack reentry phenomenon across various environments, which effectively inhibits crack propagation and improves the adhesion forces. Simulations further clarify the causes of crack nucleation and the underlying adhesion mechanisms. Demonstrations of the adhesive in skin-attachable electronics across multiple environments highlight its potential for applications in wearable electronics operating under diverse and complex conditions, promoting rapid development of wearable flexible electronics.