Design of a Flexible Weight Sensor Using Optical Fibre Macrobending

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• Flexible sensors are crucial for various applications, including wearable devices and structural health monitoring.
• Optical fiber sensors offer advantages such as immunity to electromagnetic interference and remote sensing capabilities.
• Macrobending loss in optical fibers is a known phenomenon that can be exploited for sensing applications.

Purpose of the Study:

• To develop and characterize a flexible weight sensor utilizing optical fiber macrobending loss.
• To investigate the influence of different sensor components and designs on performance.
• To establish the sensor's response linearity and tunability for weight measurement.

Main Methods:

• A sensor design employing an impactor layer with cylindrical protrusions to induce macrobending in an optical fiber.
• Experimental testing using two types of optical fibers, two impactor materials, and two impactor designs.
• Varying protrusion bend radii from 3 mm to 10 mm and applying weight loads up to 10 kg.
• Measuring optical loss in decibels (dB) as a function of applied weight in kilograms (kg).

Main Results:

• A linear relationship between optical loss (dB) and applied weight (kg) was observed for loads exceeding 2 kg.
• The sensor demonstrated a tunable response, with optical loss ranging from 0.5 dB to 25 dB for a 10 kg load.
• The proportionality constant, indicating sensor sensitivity, could be adjusted by modifying physical parameters like bend radius and material choices.

Conclusions:

• The developed optical fiber macrobending loss sensor offers a flexible and tunable solution for weight measurement.
• The sensor's linear response and adjustable sensitivity make it suitable for applications requiring accurate weight detection.
• Further optimization of sensor components and design can enhance performance for specific weight sensing requirements.