Leather-Based Strain Sensor with Hierarchical Structure for Motion Monitoring

Flexible and wearable strain sensor has drawn a great deal of attention owing to its wide applications in health monitoring, human–machine interfaces, soft robotics, etc. Microstructural design on the conductive layer of strain sensor effectively improves its performance in linearity and hysteresis effect, yet the process of achieving microstructure is complicated. Leather, a kind of conventional flexible materials to manufacture clothes, shoes, etc., possesses natural hierarchical structure that consists of collagen fiber. Herein, leather is used as a substrate to fabricate a strain sensor by filtration of conductive nanomaterials aqueous dispersion. It is found that 0D conductive nanomaterials can be adsorbed in leather to form conductive pathway with leather-like microstructure. The as-prepared sensor with such microstructure not only inherits the air permeability, mechanical property, and biocompatibility from leather, but also displays linearity performance within three regions, low hysteresis effect, short response time, high stability, stretchability, as well as good durability. Kirigami is introduced to endow the leather-based sensor with stretchability. Such a sensor is applicable to human motion monitoring and shape perception of robotic arm.