A biomimetic flexible sensor inspired by Albuca namaquensis for simultaneous high stretchability and strength

Abstract

In the realm of intelligent human-machine interaction, the expansive potential of robust flexible wearable electronic devices emerges prominently. However, the practicality of such flexible electronic devices is often constrained within scenarios involving substantial mechanical strains, such as high-intensity (>100 MPa) and high tensile (>1000%) deformation, particularly in articulation-rich joint regions. Specifically, the substrates of flexible sensors confront challenges in reconciling elongation rates and tensile strengths, for which a cogent strategy is currently lacking to address the aforementioned mechanical parameter requisites. To address this quandary, the present study employs a paradigm of microscale materials that synergistically integrate rigid-flexible coupling enhancements, coupled with a biomimetic progressively asymptotic stretch optimization approach at the macroscale structural level. Through an inside-out methodology, we have ingeniously devised a biomimetic flexible sensory electronic device that seamlessly integrates sensing media and load-bearing capabilities, uniquely poised for simultaneous deployment within high-intensity and high-stretchability scenarios. By employing a judicious combination of rigidly supporting styrene monomers and the polymerized three-dimensional scaffold, formed through the coupling of elastomeric sustaining ethylene-butadiene monomers, with the high-strength, highly conductive discrete medium of graphene, we have achieved the successful synthesis of a substrate boasting a mechanical strength of 121.4 MPa alongside an impressive 1109% elongation capacity. This substrate exhibits a remarkable electrical conductivity up to 106 S*m−1. Furthermore, drawing inspiration from the serpentine architecture of the Albuca namaquensis, a two-tiered gradient stretching approach has been harnessed, resulting in an approximate 2.8-fold enhancement in stretchability. Leveraging the ingeniously designed GSBS sensor, an online testing platform for human-machine interaction capable of accommodating substantial deformations at joint interfaces is established. Through this innovation, we have effectively orchestrated the synchronization and emulation of extensive tensile movements between mechanical prosthetics and human articulations.