An optical sensor having a cover layer, an emitter disposed on a first side of the cover, a detector disposed on the first side of said cover, and a plurality of stacked independent adhesive layers disposed on the same first side of the cover, wherein the top most exposed adhesive layer is attached to...http://www.google.com/patents/US6748254?utm_source=gb-gplus-sharePatent US6748254 - Stacked adhesive optical sensor
