Tactile sensor arrays using fiber Bragg grating sensors

This paper describes two kinds of 3 × 3 force sensor arrays using fiber Bragg gratings (FBG) and transducers for tactile sensation to detect a distributed normal force. One array is developed for a large area tactile sensor that has good sensitivity but low spatial resolution, similar to human body skin. The other is for a small area tactile sensor that has good sensitivity and spatial resolution, similar to human finger skin. The transducer is designed such that it is not affected by chirping and light loss. We also present the fabrication process and experimental verification of the prototype sensors. Experimental tests show that the newly designed sensors have good performance: good sensitivity, repeatability, and no-hysteresis. The load calibration is accomplished by a verified uniaxial load cell. In order to provide a more precise measurement, temperature compensation is applied to all taxels. These force sensor arrays are flexible enough to be attached to a curved surface and they also have simple wiring compared with other types of small force sensors for tactile sensation.