Flexible and self-healing piezoresistive sensor based on balsa wood aerogel and shear-stiffening gel

Wearable electronics used to capture biological signals are of substantial importance in health monitoring, smart protection, human-computer interaction. However, the development of durable, stable, and high-performance flexible sensors remains challenging, as materials are susceptible to deformation or rupture under external effects. Herein, an improved preparation strategy is proposed, it employs balsa wood aerogel as the skeleton of the flexible sensor, incorporates shear-stiffening gel (SSG) to enhance the mechanical strength and durability of the material. The highly conductive carbon black (CB) network dispersed within balsa wood aerogel-SSG ensures the stability of the flexible sensor. By investigating the effect of SSG and CB on the compression and sensing performances, the optimized CB-SSG-balsa wood aerogel flexible sensor (CBSSG-FS) exhibits a wide response range of 0–20%, a short response time (82 ms), and good cyclic stability (over 150 cyclic tests), benefiting from the natural morphology of balsa wood aerogel. Moreover, the filled shear-stiffening gel endows the sensor with an excellent self-healing characteristic, enabling the stable output of sensing performance after four-cycle impact. Therefore, a flexible, durable and self-healing balsa wood aerogel sensor is fabricated, showing its potentials in physiological health tracking, motion detection and danger warning. • A novel balsa wood-based flexible sensor was fabricated. • The sensor exhibits a wide response range, short response time and excellent cyclic stability. • The sensor shows excellent self-healing characteristic, enabling the stable output after four impacts. • A synergistic effect exists between the natural morphology of balsa wood aerogel and shear-stiffening effect of SSG.