A membrane switch has a substrate and a plurality of first conductors formed on the substrate. A flexible membrane having a plurality of second conductors formed thereon is positioned relative to the substrate by a spacer which may be adhesively secured to both membrane and substrate. There are openings...http://www.google.com.au/patents/USRE31332?utm_source=gb-gplus-sharePatent USRE31332 - Membrane switch with means for preventing contamination of the interior thereof
