External force sensor and manufacturing method thereof

External force sensor that detects the magnitude and position of external force using optical power loss in a U-shaped optical waveguide

This technology detects the magnitude and position of an external force by arranging an optical sensing unit, composed of a flexible waveguide body and a core, in a U-shape to measure optical path deformation and optical power loss caused by external pressure.

Existing sensors for robot grippers are difficult to miniaturize due to their complex structures, involve complicated manufacturing processes, and incur high production costs, along with issues related to sensor calibration.

This technology is an optical sensor structure that features a flexible waveguide sensing unit wrapped in a U-shape around an inner layer, with light-emitting and light-receiving grooves at both ends of the sensing unit, and is covered by an outer layer and a protective plate to facilitate force transmission and sensor protection. It can be applied to robot grippers, tactile sensing, and precision measurement, enabling miniaturization and simplified manufacturing while providing precise detection of external forces.

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Key Features:

• First and second external force sensing units arranged to wrap around the longitudinal ends of the inner layer in a U-shape
• Each external force sensing unit includes a flexible waveguide body and a core inserted inside to provide an optical path
• The first and second external force sensing units are provided with different light sources and are configured to be spaced apart from each other at the ends of the inner layer
• A plate covering the gap between the first and second external force sensing units formed at the ends of the inner layer

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This invention was developed with support from the Ministry of Trade, Industry and Energy for inflatable soft robotic arm technology for the care of the elderly and patients.