Selectively Actuated Fiberbots for High-precision Minimally Invasive Surgery

Jinshi Zhao, Libaihe Tian, Alex Ranne, Qindong Zheng, Yue Li, Xiaotong Guo, Ziqi Yang, Ali Anil Demircali, Mohamed E. M. K. Abdelaziz, Bruno Gil Rosa, Ferdinando Rodriguez y Baena, Burak Temelkuran · N/A · 2026

Summary

Abstract Summary

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 $\mu$m. 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.

Key Points

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 $\mu$m.
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.

METHODS

The fiberbot body design consists of a tubular polymeric structure with an outer diameter of 1.9 mm and an inner diameter of 1 mm, adapted to accommodate commercially available fiber-based surgical instruments, such as surgical laser fibers. Nine side lumens are uniformly distributed around a central channel to accommodate metallic wires.

Three triplets of 60 $\mu$m metallic wires, arranged as ’copper–stainless steel–copper’, were embedded within these side channels for actuation and power transmission (Fig. 1 ).

METHODS — Selectively Actuated Fiberbots for High-precision Minimally Invasive Surgery — Fig. 1: Schematic diagram of the selectively actuated fiberbot.

EXPERIMENTAL EVALUATION

To control and actuate the fiberbot, the adapter connected to the fiber was interfaced with a buffer circuit consisting of six operational amplifiers (op-amps). These op-amps provided voltage amplification and impedance matching between the control system and each of the actuation wires.

The input of the buffer circuit was connected via jumper wires to the digital-to-analog converter (DAC) ports of a real-time controller (cRIO-9025, National Instruments, USA). The control system was developed within the LabVIEW environment (Fig. 4 (a)) [ 4 ] .

EXPERIMENTAL EVALUATION — Selectively Actuated Fiberbots for High-precision Minimally Invasive Surgery — 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.

Sources and Demonstrations

Figures are reproduced from Zhao et al. See the full paper for experimental details and the project page, when the paper links one, for demonstrations and videos.