Reflection-based lab-in-fiber sensor integrated in a surgical needle for biomedical applications

Area of Science:

• Optofluidics
• Biomedical Sensing
• Fiber Optic Sensors

Background:

• Lab-in-fiber (LIF) sensors offer integrated multiphysics sensing in compact spaces.
• Existing LIF sensors have limitations in size and simultaneous multi-parameter detection.

Purpose of the Study:

• To design and manufacture an ultra-short, multiparameter lab-in-fiber sensor.
• To demonstrate a "touch and measure" approach for biomedical applications.

Main Methods:

• Fabrication of a sensor combining an in-fiber air microcavity and a plane-by-plane fiber Bragg grating (FBG).
• Integration of the sub-300 µm sensor onto the tip of a single-mode fiber and into a surgical needle.

Main Results:

• Simultaneous detection of axial tensile strain (6.69 pm/µε) within the air cavity.
• Simultaneous detection of surrounding refractive index (11.5 nm/RIU) using the FBG.
• Demonstration of the first ultra-short LIF sensor utilizing a "touch and measure" strategy.

Conclusions:

• The developed ultra-short LIF sensor enables simultaneous measurement of strain and refractive index.
• This technology holds significant potential for in-situ biomedical sensing and diagnostics.
• The "touch and measure" approach offers a novel method for real-time data acquisition in biomedical applications.