A Fiber-Optic Mechanoreceptor in a Finger-Shaped End Effector for Human-Like Tactile Sensing

An artificial mechanoreceptor based on a hetero-core fiber-optic sensor has been developed using a reflective-type sensor element for realizing human-like sensations for multiple tactile information on artificial structures. The proposed mechanoreceptor is embedded in a finger-shaped end effector as a pseudoartificial finger in order to evaluate how the end effector responds to a variety of tactile information. The end effector can detect contact forces in the range of 0.02-4 N with a maximum force sensitivity of 3.23 dB/N and is sensitive in a local area contact within 2 mm, which is comparable with the spatial resolution of human fingertips. The end effector can also detect vibrations at frequencies up to 1 kHz. The developed end effector is also tested in assessing the hardness of a soft resin material in the range of 5°-80° on the Shore A hardness scale, and in discriminating surface conditions when scanned across a surface.