Angle Sensor for Minimally Invasive Surgical Robot Based on Surface Plasmon Resonance with Kretschmann Prisms

This study proposes a bimetallic Ag-Au sensor through a comparative analysis with traditional Ag-only membrane sensors and Au-only membrane SPR sensors. Innovative use of SPR sensors for angular change measurement, especially in minimally invasive robotic surgery in medicine. The research findings indicate that the Ag film sensor exhibits the highest sensitivity, while the bimetallic Ag-Au sensor demonstrates superior sensitivity compared to the Au-only sensor. Furthermore, the stability of the bimetallic Ag-Au sensor surpasses that of the Ag-only sensor. After evaluating the performance parameters based on experimental and simulation results, the sensor with 40 nm Ag and 10 nm Au film thickness is identified as the optimal design. Experimentally verified, this configuration yielded the best sensing performance, with a sensitivity of 628.95 for changes in folding angle. This represents a 275.64% improvement over the pure Au sensor and a 210.43% enhancement over the pure Ag sensor in terms of sensitivity for angle changes.