Vision-based Tactile Sensing
GelSight achieves a high-precision tactile sensing. It can even detect fingerprints.
GelForce at Tachi Lab utilizes a transparent elastic material, two layers of blue and red markers, and a camera. When a user touches GelForce, the blue and red markers are distorted. The camera acquires the image and calculate the magnitude and direction of the applied force.
Hairy Tactile Sensing
Fibratus tactile sensor provides a new way of sensing mothers’ soft touches. This hairy (furry?) sensor is composed of flexible fibers, silicon rubbers, patterned surfaces and a CCD camera.
 S. Saga, S. Kuroki, N. Kawakami, and S. Tachi, "Fibratus tactile sensor using reflection on an optical lever," in SIGGRAPH 2007 Emerging Technologies, 2007. http://files.tachilab.org/intconf2000/saga200708SIGGRAPHETECH.pdf
Fabric User Interfaces
Robot Skins (A.K.A Eskins or Electronic Skins)
Updated Feb. 28, 2010
Capacitive Tactile Sensor
polymer based flexible capacitive tactile sensor array at Micro Technology Laboratory, University of Washington