Here are some helpful search terms to use in research of the membrane switch industry,

Membrane switch panels
Tactile membrane switch
2-shot molding
Adhesive Back lighting
Backlighting close tolerance printing
Conductive silver control panels
Discrete switches
Domes
El lamps backlighting
Fiber optic lamps
Hybrid keypads
Input devices
Interface products
Keyboard
Hybrid keyboards
Hybrid keypads
Hybrid keyswitches
Membrane keyboards
Membrane keypads
Membrane switches
Membrane keyswitches
Membrane metal domes
Membrane poly domes
Membrane polyester domes
Membrane polymer thick film
Membrane pressure sensative adhesive 
LED’s switches
Membrane tactile domes
Pressure sensitive adhesive acrylic adhesives
Polycarbonate lexan
Conductive rubber technology
Touch screens
Capacitive touch screen
Resistive touch screens
Overlays
Graphic overlays
Spacer Dome
Printed resistors
Embedded LED’s
Keyswitches
Rugidized
Splashproof Emi/rfi ESD
Tactile domes
Tactile switches
Tactile graphic
Printed resistors
Surface mount
El lamps
Fiber optic lamps
Stock switches
Touchscreens
Touch screen keyboard
Vandal resistant
Graphic Overlay
Overlay Graphic
Circuit Conductive