Development of a contact width sensor for tactile tele-presentation of softness

This paper presents a tele-presentation system for tactile softness. Tactile softness was estimated at a remote site, which was then reproduced at a master site, by focusing on change of contact width between a fingertip and an object. To realize the tele-presentation system, a new contact width sensor was developed based on an optical principle. The sensor was designed to have a soft structure to resemble human fingers. The prototype sensor was evaluated for five different samples. The result showed that the sensor could discriminate five samples from the contact width variation, although one pair of samples showed only a slight difference. The tele-presentation system that integrates the developed contact width sensor and a newly designed softness display was developed and evaluated. The evaluation result showed that a user can discriminate softness of a remote object using this system, although the perceived softness feelings did not perfectly match the real feelings of the remote objects, which would be due to insufficient optimization of the contact width sensor. This would be improved by improving the sensor to have a similar dimensions and stiffness as real human fingers, which will be addressed in our future work.