Strain-insensitive Stretchable Triboelectric Tactile Sensors via Interfacial Stress Dispersion

The accuracy and reliability of flexible tactile sensors are often compromised by the deformation of functional materials and fluctuations in the structureactivity relationship during bending or stretching. In this work, a highly strain-insensitive stretchable triboelectric tactile sensor (SS-TTS) is developed via an interfacial stress dispersion strategy. By integrating softness-stiffness materials with an interfacial circular structure (ICS), the concentrated interfacial stress is induced to disperse onto a soft substrate, effectively suppressing strain in the sensing region during stretching. When the optimal geometric parameters of ICS (n=10, d = 6.0 mm) are used, the sensor demonstrates ultrahigh strain insensitivity (98%) in the stretchable range of 0~70% with a wide pressure range up to 150 kPa. Furthermore, the SS-TTS is seamlessly incorporated into a wearable wristband for precise monitoring of pulse signals regardless of human wrist size. This demonstrates its potential for personalized health monitoring applications. Additionally, a 3×3 triboelectric sensor array is constructed to function as a strain-insensitive stretchable touch panel for tactile imaging and trajectory recognition, further expanding the sensor's versatility. This work paves the way for the future design of stretchable electronics tailored for intelligent sensing applications under deformable conditions.