Magnetic Self-Assembled Pearl Necklace-like Microstructure for Improving the Performance of a Flexible Strain Sensor

Flexible strain sensors have important applications in wearable devices, electronic skin, robotics, and virtual reality. However, simple and effective methods to adjust the sensing performance for various applications are still the key to their commercialization. Here, a flexible strain sensor with a magnetic self-assembled pearl necklace-like microstructure is proposed, named PNS-C, which effectively improves its strain sensing performance by utilizing the curing magnetic induction intensity to adjust the arrangement of nanoparticles and multiwalled carbon nanotubes. It exhibited high sensitivity (GF = 361.02, 125–150% strain), nearly 40.16 times that of the corresponding randomly distributed structural composites, fast response (loading delay time was 132 ms), and high durability (1050 cycles). The sensing properties of PNS-C enable wearable health monitoring including facial micro-motion and knee movements. Finally, a manipulator grasping motion detection system is designed to demonstrate the potential practical value of the sensor in the field of robot control.