Editing Keyboard technology (section)

=== Membrane ===
{{Main|Membrane keyboard}}
[[File:AppleDesign Keyboard (NMB,B) -- membrane assembly 4.jpg|thumb|right|A typical membrane assembly]]
A common membrane design consists of three layers. The top and bottom layer have exposed electrical matrix traces, and the middle layer is a spacer to prevent current from passing through the top and bottom conductive traces passively. When pressure is applied to the top membrane, it bridges the top and bottom conductive contact pads, allowing current to transfer.

Two of the most common types of membrane keyboards include full-travel rubber dome over membrane and flat-panel membrane keyboards. Flat-panel membrane keyboards are most often found on appliances like [[microwave oven]]s or [[photocopier]]s.

==== {{anchor|Dome-switch keyboard}} Rubber dome over membrane ====
[[File:Rubber dome over membrane, exploded.svg|thumb|center|Exploded view of a typical rubber dome over membrane design]]
Full-travel rubber dome over membrane keyboards are the most common keyboard design manufactured today. In these keyboards, a rubber dome sheet is placed above the membranes, ensuring that the domes align with the contact pads. The rubber dome serves a dual purpose: it acts as a tactile return spring and provides a soft surface to transfer force onto the top membrane. To bridge the connection between the two contact pads, the rubber dome must be fully depressed.

Rubber dome over membrane keyboards became very popular with computer manufacturers as they sought to reduce costs while PC prices declined.

===== Scissor-switch =====
{{See also|Chiclet keyboard}}
[[File:Scissor switch mechanism.svg|thumb|Scissor switch mechanism]]
A common, compact variant of rubber dome over membrane is the scissor-switch, based on the [[scissors mechanism]]. Due to the requirement of many notebooks to be slim, they require the keyboards to be low-profile. Therefore, this technology is most commonly featured on notebooks. The keys are attached to the keyboard via two plastic pieces that interlock in a "scissor"-like fashion and snap to the keyboard and the keycap. These keyboards are generally quiet and the keys require little force to press.

Scissor-switch keyboards are typically slightly more expensive. They are harder to clean (due to the limited movement of the keys and their multiple attachment points) but also less likely to get debris in them as the gaps between the keys are often smaller (as there is no need for extra room to allow for the 'wiggle' in the key, as typically found on a membrane keyboard).<ref>{{Citation |title=Keyboards |access-date=21 April 2009 |archive-url=https://web.archive.org/web/20120222204455/http://www.ergocanada.ca/ergo/keyboards/mechanical_vs_membrane_keyswitches.html |url-status=live |contribution=Mechanical vs membrane keyswitches |contribution-url=http://www.ergocanada.ca/ergo/keyboards/mechanical_vs_membrane_keyswitches.html |place=[[Canada|CA]] |publisher=Ergo |archive-date=22 February 2012}}.</ref>{{clear}}

==== Flat-panel membrane ====
[[File:Atari 400 keyboard.jpg|thumb|Atari 400 keyboard]]
Flat-panel membrane keyboards are often used in harsh environments where water or leak-proofing is desirable. They can have non-tactile, polydome tactile and metal dome tactile keys. Polydome tactile membrane switches use polyester, or PET, and is formed to create a stiff plastic dome.  When the stiff polydome is pressed, the conductive ink on the back of the polydome connects with the bottom layer of the circuit. Metal dome membrane switches are made of stainless steel and offer enhanced durability and reliability and can feature custom dome designs.<ref>{{cite web | url=http://www.dotkeys.in/membrane-keyboards.html | title=Dotkeys &#124; Membrane Switches }}</ref> Non-tactile flat-panel membrane keyboards have little to no keypress feel and often issue a beep or flash of light on actuation.

Although this keyboard design was commonly used in the early days of the [[personal computer]] (on the [[Sinclair ZX80]], [[ZX81]], and [[Atari 400]]), they have been supplanted by more responsive and modern designs.

==== Roll-up keyboard ====
[[File:Foldable keyboard.jpg|thumb|Most keyboards are rigid, but this keyboard is flexible.]]
{{See also|Roll-away computer}}
Computer keyboards made of flexible silicone or polyurethane materials can roll up in a bundle. This type of keyboard can take advantage of the thin flexible plastic membranes, but still pose the risk of damage. When they are completely sealed in rubber, they are water resistant. Roll-up keyboards provide relatively little tactile feedback. Because these keyboards are typically made of silicone, they unfavorably tend to attract dirt, dust, and hair.<ref>{{cite web | url=https://keyboardsexpert.com/roll-up-keyboards/ | title=Roll-Up Keyboards - What are They and Are They Durable? | date=12 November 2021 }}</ref>{{clear}}