A Novel Fiber Bragg Grating Three-Dimensional Force Sensor for Medical Robotics

This article introduces a novel Fiber Bragg Grating (FBG) 3-D force sensor designed for the end-effectors of medical robots. The sensor incorporates a specially designed layered elastic structure, achieving miniaturization, structural self-decoupling, and high-sensitivity 3-D force measurement through a cleverly compact spatial design and a reasoned layout of 5 FBGs. The construction of the theoretical model successfully decouples temperature and force. Simulation experiments determine the sensor&#x0027;s operational frequency range to be 0&#x2013;403.6&#x00A0;Hz, validated through rapid prototype verification using 3-D printing technology. Static experiments reveal that the sensor&#x0027;s maximum measurement range and minimum resolution are <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula>5&#x00A0;N and 4.95 mN, respectively. The maximum sensitivity and minimum interaxis coupling are determined to be 201.86 pm/N, 0.01&#x0025;F.S.(Fy&#x2013;Fz), respectively. In dynamic experiments, The minimum tracking error is 3.89&#x0025; F.S and successfully adapts to the end-effector of a robotic arm. Remarkably, the sensor excels in force detection during medical palpation and acupuncture procedures, validating its effectiveness and practicality in real-world applications. This study presents a reliable and high-performance end-effector force-sensing solution for the field of medical robotics.