Stretchable, Self-Healable, Carbon-Based Strain Sensor for Soft Robotic Applications

Recent advancements in strain sensor technology are expanding their applications in fields such as soft robotics. A significant advantage would be if these sensors could self-heal completely, especially when damaged in the active area, potentially reducing or completely eliminating maintenance costs. Here, to address this, a self-healable strain sensor was created using silicon tape and a self-healable conductive carbon composite. Initially, the pristine device showed a gauge factor (GF) of 11.3 with a maximum stretch of 50%. It was then intentionally cut and healed at room temperature without external additives to demonstrate its self-healing capability. After healing, the composite material regained its original resistance, but the strain sensor showed an increased resistance of 166.5% (423.55 to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1128.85\Omega)$</tex>. The strain sensor also demonstrated a GF of 17.4, indicating its sensitivity to strain, even with a 10% stretch, as confirmed by electromechanical testing. This highlights the potential for self-healable sensors to recover functionality post-damage, offering cost savings, improved durability, and reduced downtime.