Stretchable Curvature Sensors for Motion Capture with Bending-Stretching Coupling Deformation

Accurate curvature sensing is essential for robotic control, movement monitoring, and enhanced interactive experiences. Existing strategies rely either on stretchable strain sensors, which introduce non-calibratable measurement errors due to unstable interfacial friction and slippage, or on non-stretchable curvature sensors, which lack the stretchability required for wearable applications. Here, a stretchable curvature sensor is reported featuring a core component of a wave-shaped symmetrical laminated structure. This structure achieves both stretchability and effective decoupling of bending from stretching, enabling accurate curvature measurement under frictional conditions. Slip-simulation tests with smart gloves demonstrated a 93.6% reduction in measurement errors relative to conventional strain sensors. These results underscore the sensor's promise for applications in flexible wearable devices and soft robotics.