Three-dimensional cracks architectural design enhances the sensitivity and stretchability of superhydrophobic strain sensors
Zhizhe Liu, Qin Jin, Changgeng Zhuang, Peiying He, Yangchengyi Liu, Xiufeng Wang, Xiaoping Ouyang
Abstract
Crack-based strain sensors, inspired by spider's sensory system, show high sensitivity, making them suitable for detecting tiny deformation signals from human body. However, enhancing their adaptability to various body deformations and complex hydrated environments remains a challenge. We devise a three-dimensional crack (3D-crack) architectural design with cut-through cracks in the front conductive layer ensure high resistance changing and side network cracks maintain sensing performance under larger tensile strains to balance the trade-off between stretchability and sensitivity while the controlled crack evolution and reduced lateral deformation-induced resistance change solve issues of low-fidelity and high-hysteresis. The preparation of the conductive layer involves spontaneous aggregation and migrating of graphite particles and liquid Ecoflex, forming a conductive layer with exceptional superhydrophobicity and excellent waterproof properties. As a result, the developed 3D-cracks strain sensors exhibit excellent sensing performance in terms of a large stretchability (up to 100 %), high sensitivity (GF = 1084.16), low hysteresis (<0.47 %) and low overshoot response (<5 %). The fabricated sensor demonstrates its capability to monitor various body deformation in complex hydrated conditions even underwater, suggesting the potential of this straightforward technique for producing wearable sensors capable of capturing full-range human motion signals in aquatic settings.