Selectively Actuated Fiberbots for High-precision Minimally Invasive Surgery
Authors: Jinshi Zhao, Libaihe Tian, Alex Ranne, Qindong Zheng, Yue Li, Xiaotong Guo, Ziqi Yang, Ali Anil Demircali, +4 more
Organizations: Department of Metabolism, Digestion and Reproduction, Imperial College London, SW7 2AZ, UK · Hamlyn Centre for Robotic Surgery, Imperial College London, SW7 2AZ, UK · Department of Bioengineering, Imperial College London, SW7 2AZ, UK · Department of Biomedical Engineering, University of Glasgow, G12 8QQ, UK
Long, slender instruments are essential for minimally invasive surgery (MIS), but achieving precise distal manipulation becomes increasingly difficult when actuation extends along the entire instrument. Here, we present an electrothermally actuated fiber-based robot designed for MIS procedures, in which Joule heating is concentrated in the distal active segment. The fiber is fabricated using a thermal drawing process and uses embedded metallic wires for thermal actuation. This robotic fiber, 1.9 mm in diameter and 1.2 m in length, can precisely manipulate surgical laser fibers with positional precision below 100 μm. The compact size of the fiber robot allows it to pass through the working channel of a flexible endoscope, while keeping both devices mechanically uncoupled to allow independent motion. A phantom demonstration combining the robotic fiber with a da Vinci instrument conceptually demonstrated its compatibility with existing endoscopic systems for clinical applications. Our robotic fiber enables precise distal motion and holds the potential to improve clinical outcomes by enhancing precision in MIS procedures.
Figures & tables
Fig. 1: Schematic diagram of the selectively actuated fiberbot.
Fig. 2: Fiber fabrication. (a) Schematic diagram of the thermal drawing process, showing wire spools feeding wires during drawing. (b) Cross-sectional design of the fiber. (c) Microscopic image of the fiber cross-section with exposed wires.
Fig. 3: Selectively actuated Fiberbot with handle.
Fig. 4: Fiberbot motion characterization. (a) Fiberbot actuation and characterization setup. (b) Fiberbot tip positions resulting from 500 random input voltage sets. Each color represents one of the three possible combinations of two simultaneously actuated wire sets. (c,d) Relationship between applied voltages (c), powers (d) and the vector magnitude of the fiber tip position along their corresponding actuation directions. (e,f) Measured (blue) versus desired (orange) spiral and star shape paths.
Fig. 5: Temperature characterization. (a) A series of thermal imaging camera images showing the temperature distribution of the fiber at various applied voltages. (b) Maximum (orange) and minimum (blue) temperatures at various applied voltages measured using a thermal camera. (c) Fiber tip displacement (blue) and temperature difference (orange) between maximum and minimum temperatures under various applied voltages. (d,e) Thermal camera setup and corresponding image showing a side view of the selectively actuated fiber.
Fig. 6: Comparison of the required actuation power between the selectively actuated fiberbot developed in this work and the fiberbot reported in the previous work [ 4 ] . (a) Schematic of the working principle of the selectively actuated fiberbot developed in this work. (b) Schematic of the actuation approach used in the previous work. (c) Calculated total actuation power required to achieve a 2 mm tip displacement for different passive-section lengths.
Fig. 7: The da Vinci® surgical instrument integration and endoluminal phantom demonstration. (a) The integration between the da Vinci® surgical robot and the fiber actuator. (b) Experimental setup of the abdominal phantom study. (c) Retraction of the phantom surface layer using a grasper to expose the simulated tumor. (d) Fiberbot tip scanning along the simulated tumor boundary, with an optical fiber inserted through its central lumen. (e) Fiberbot tip motion path around the simulated tumor, indicated by the red trace.
May 29, 2026·Shuyuan Yang, Grant Boone, Timo Markert +4Surgical Robotics
Department of Electrical, Computer, and Systems Engineering, Case Western Reserve University, Cleveland, OH 44016, USA · Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106, USA · Resense GmbH, Germany +3