Touch-sensitive membrane switches are a user-friendly option for incorporating electronic controls into many machines and types of equipment. They can be custom designed for optimal fit and function in many applications from vehicles to medical equipment to automated CNC machines, appliances, and more. Their sealed construction also protects against moisture, dust, and debris, making them easy to clean without damaging the circuitry inside.
By printing, cutting, and laminating a very thin plastic film over a control, users can activate machinery and control processes that are tied to the switches beneath the surface. With just a slight amount of pressure from their fingertip, operators can actuate buttons on the panel, creating a signal that goes to a microprocessor-based control system. Membrane switches reduce the physical force and fatigue required, which is especially important for repetitive tasks.
At Techprint, we design, print, manufacture, and assemble custom membrane switches and graphic overlays for applications in many industries. Here we’ll look at some important considerations for effective and intuitive design.
The Importance of Device Feedback for End Users
There are many configurations and materials available for customizing membrane switches for an application. In most cases perfecting the underlying circuitry and the actions it controls drives many design decisions. However, membrane switches are also user interface devices with productivity and safety implications. How, and how easily, users interact with them is critical. The ways in which a device provides feedback in response to switch activation is a large part of their utility.
For example, most of us notice the keys on some computer keyboards feel more springy or firm, have a louder click or a flatter or more curved key surface. These responses from the device tell the user definitively if a button was activated or not, if the equipment is powered on, and so forth. Feedback considerations at play in membrane switch design include:
- Tactile: raised or embossed buttons, clusters of buttons grouped by function, spacing of embossed buttons, the feeling of resistance of the button as it is depressed, or how the button feels when it snaps back under the user’s finger, overlay textures or raised printing.
- Visual: LED indicator lights, text or images that display on an LCD screen when a button is depressed, color and graphic design, organization of switches on the overlay, embossed or flat surfaces.
- Auditory: Clicking or snapping sounds when buttons are depressed and released, beeps or other sounds that indicate the switch has been activated.
Types of Membrane Switches
At Techprint, we create membrane switches with low force requirements, excellent tactile feedback, and colorful overlay options. These are four popular types of membrane switches we produce:
Non-Tactile Membrane Switches
Non-tactile switches feel like a smooth touchscreen, with no direct tactile feedback. This design is straightforward and cost-effective, making it an excellent choice for projects with a tight budget. Non-tactile membrane switches can be made in custom shapes and dimensions for non-traditional applications. The switches can also be paired with visual cues like shadowed keys for visual feedback.
Tactile Membrane Switches
Tactile membranes create a physical snapping sensation when depressed, allowing users to verify that a button is fully actuated. Techprint uses high-quality conductive stainless steel snap domes to create this snap action without the need for a flexible upper circuit layer. Switches can also include a thin backing to prevent dome inversion and extend service life.
Hydro-formed polydomes are also available. These have less pronounced tactile feedback. Both materials perform reliably in standard operating conditions, though polydomes may not be suitable for extreme temperature environments.
Mixed Panels
We can also manufacture panels with both non-tactile and tactile membrane keys for applications that require large switches or have concealed maintenance and programming switches.
PCB-backed Membrane Switches
For a compact and versatile keypad solution, we offer membrane switches with a printed circuit board (PCB) for the lower circuit. These boards can hold multiple surface-mounted components bonded directly to the PCB, and the PCB itself provides structural support.
Optional Features
Techprint can incorporate additional features into membrane switches to enhance durability and functionality, such as:
- Ruggedized materials and construction for challenging environments.
- Plastic housings.
- Flat or embossed switches.
- Rigid or flexible substrates.
- Embedded EMI shielding from aluminum foil, copper foil, or printed conductive ink.
Materials
We begin all projects with an assessment of OEM requirements and explore options for the best combination of materials. We also select from a variety of options for the following membrane switch panel components:
- Adhesives. Pressure-sensitive adhesive choice depends on operating conditions , outdoor exposure, LSE vs HSE surface energy, and the other materials in the assembly.
- Film or substrate. Precision polyester films form a durable, flexible layer to hold the circuitry.
- Ink. We use conductive and dielectric inks made with silver and carbon that protect the circuitry and provide insulation.
Graphic Overlays
The visual and textural qualities of the overlay significantly impacts the appearance and user-friendliness of membrane switch assemblies.
Visual Elements
The overlay is the colorful, printed surface layer that indicates where buttons and switches are located, labels their functions, and provides visual cues to how controls are organized. Branding and decorative effects can also be incorporated. Techprint offers a large selection of colors and can print different size overlays with lines and text in many fonts, designs, and thicknesses.
Display Windows
Integrated display windows and LED indicators provide visual feedback and other helpful information for users. Single point and block LEDs are compatible with any surface finish, but work best with matte and textured surfaces. LEDs do not actually penetrate up through the top of the tactile switch surface; however, clever design techniques create a seamless look. We can also include integral or surface-mounted single-point LEDs for colorful displays with an embossed or unembossed graphic layer.
Additional options include:
- Matte or glossy finishes.
- Translucent filtering inks.
- Uncolored LCD windows.
- Red LED displays or green or amber filters for low-light conditions.
- Gray LEDs and filters for bright conditions.
- Deadfronted or hidden screens for use against a dark background.
Selective Texturing
In high-traffic area or heavy-duty applications, consider adding a scratch-resistant, selective texturing layer to add clarity and protection. Textured hardcoats can work on glossy or anti-glare display windows.
Membrane Switches from Techprint
Membrane switches are an intuitive, durable solution for control panels on commercial, consumer, and industrial machinery and devices. Techprint specializes in manufacturing and supplying custom membrane switch panels. Explore our custom manufacturing capabilities today to get fast, high-quality solutions straight from our 55,000-square-foot Massachusetts facility. Contact us to learn more about our capabilities or request information to start your next project.