Thickness-induced gradient micro-wrinkle PDMS/MXene/rGO wearable strain sensor with high sensitivity and stretchability for human motion detection

Flexible strain sensors have garnered considerable attention in the domains of health monitoring, human–machine interaction, and electronic skin due to their exceptional stretchability, flexibility, skin conformability, and superior sensing capabilities. Despite recent advances, developing high-performance strain sensors that combine high sensitivity, a wide strain range, and robust stability remains a significant challenge. To overcome this, we have innovatively developed a polydimethylsiloxane (PDMS)/MXene/reduced graphene oxide (rGO) strain sensor using a tilt-filtration method and a pre-stretching technique. This sensor features a novel gradient micro-wrinkle structure, induced by variations in thickness, which enhances its strain sensing capabilities and imparts superhydrophobic properties. The synergistic interaction between the materials and the microstructure enables the sensor to achieve a high sensitivity (gauge factor (GF) peaking at 136,124.40), a wide strain range (up to 300%), and excellent stability (up to 10,500 cycles at 10% strain). Capable of detecting a wide array of human body movements, from large-scale motions to subtle stimuli, this strain sensor also boasts a rough surface texture and low surface energy, conferring superhydrophobicity and corrosion resistance . These features make it suitable for use in harsh environments. The gradient micro-wrinkle strain sensors hold promising potential for practical applications in health monitoring, electronic skin, and human–machine interaction.