Highly robust mechanical sensing platform inspired by a scorpion structure for 3D-mechanical signal perception

Abstract

Three-dimensional force sensors play a crucial role in the aerospace industry and precision mechanical manufacturing. However, the current sensors still lack sufficient stability in the sensing of spatial mechanical forces and struggle to distinguish dynamic and static pressure signals. Coincidentally, scorpions in nature show a remarkable capacity to perceive three-dimensional stress with exceptional stability and sensitivity. This is primarily attributed to the highly sensitive sensing structure and stable multilayer structure in the slit sensilla of a scorpion. Inspired by this design, we develop a biomimetic sensing platform capable of accurately detecting the magnitude, position, and loading rate of a spatial force. This bionic system consists of an alternating combination of carbon fiber board (CFB) and hydroxylated multiwalled carbon nanotubes-styrene–isoprene (HMCNSI). Specifically, the flexible HMCNSI polymer enhances fatigue resistance, while the rigid CFB offers support and protection, resulting in exceptional robustness and stability of the sensing platform. The platform exhibits a rapid response time (14 ms), a fast recovery time (28 ms), and excellent sensitivity (GF = 46 for strain 0–3 %; GF = 118.3 for strain 3–6 %). Furthermore, the mechanical sensing platform can distinguish dynamic and static loads, identify exertion force rates in the range of 0.1–1 m/s and force magnitudes within 30 N, and provide a high positioning accuracy of 1 mm. The proposed biomimetic sensing platform exhibits promising applications in the field of precision detection of spatial forces such as human-machine interactions and intelligent robotics.