Touch Membrane

Membrane touch switches are sometimes referred to as membrane switches or touch switches. Generally, a membrane touch switch is a momentary electrical on/off switch for activating and de-activating a circuit. Membrane touch switches are thought to have momentary action because they operate under conditions of normally open, push to close, and immediate opening. This means that the switch must be pressed, either with an actuator or with a finger, so that its two poles make direct contact to close the circuit. When the membrane touch switch is released, the poles immediately separate and the switch returns to its original open

 

Membrane touch switches are manufactured by printing silver or carbon ink onto heat-stabilized polyester film. An overlay is applied to the first surface of the switch as the graphic interface. Because these top substrates are made from thin, pliable materials, they are referred to as “membranes” or “graphic overlay films.” Membrane touch switches are used in a variety of industries, ranging from medical to aerospace applications to consumer markets. They also may be used in industrial control systems. Often, membrane touch switches are used in appliance switches, computer keyboards, touch-sensitive toys, and phones. Membrane touch switches are becoming the norm in manufacturing and engineering industries because they enhance the aesthetics of human-machine interfaces while costing less and being more durable than other types of switches.

 

Construction of Membrane Touch Switches

While membrane touch switches may look very different as aesthetics may or may not be a consideration for their application, the basic construction of a membrane touch switch is the same.

 

Specification:

 

 

  • Graphic overlay
  • Graphic adhesive
  • Top circuitry
  • Spacer adhesive
  • Bottom circuitry
  • Backer adhesive
  • Rigid support layer

 

 

Features:

 

  • High conductivity
  • Flexibility
  • Silver and carbon conductors
  • Strong adhesion
  • Fast curing
  • High reliability

 

There are actually three different types of  Touch Membrane:

  1. Capacitance: like capacitive smartphones, capacitance switches use the body’s capacitance to identify touch and open/close the circuit. They require only one electrode to operate, which is typically found behind a panel made of non-conductive material like glass or plastic.

 

  1. Resistance: this type of membrane touch switch features two electrodes, both of which need to be in contact with a finger or other electrically conductive material to work. Touching the switch creates an open or closed state. Resistance switches feature a more simplistic design than their capacitance counterpart.

 

  1. Piezo: perhaps the least common type of membrane touch switch, piezo switches live up to their namesake by using the piezo ceramic bending properties. They are constructed behind a panel or surface, allowing the switch to work with a wide variety of materials. Piezo touch switches are unique in the sense that they can be used as an actuator.

 

 

Advantages

  • Sleek Appearance
  • Robustness and Durability
  • Ease of Maintenance
  • Flexibility in Customization
  • Light Touch Activation
  • Scroll and Slider Designs
  • Multi Touch Capability
  • Curved Interface Design
  • Flexibility in Functions and Communication Interfaces
  • Backlighting Options

 

Application:

  • Medical Devices
  • Portable Devices
  • Appliances
  • Consumer Electronics
  • Personal Computer
  • Gaming
  • Hospitality
  • Industrial
  • Kiosk

 

Reference:

http://www.nelson-miller.com/what-is-a-membrane-touch-switch/

https://robu.in/product/4×4-matrix-keypad-membrane-switch-arduino-arm-mcu/

https://forum.arduino.cc/index.php?topic=24352.0

https://www.instructables.com/id/Connecting-a-4-x-4-Membrane-Keypad-to-an-Arduino/