The invention relates to a tactile sensor capable of obtaining information for a plurality of degrees of freedom at each point on a surface by introducing multi-channel sensing that uses color or optical spectrum to an optical tactile sensor. An optical tactile sensor is provided with a tactile section...http://www.google.de/patents/US6909084?utm_source=gb-gplus-sharePatent US6909084 - Optical tactile sensor having a transparent elastic tactile portion
