What is the difference between a capacitive and resistive touch screen?

The touch screen technology has evolved rapidly during the last few years, bringing users and businesses many options to choose from. While new types of touch screens emerge and others are improved, the resistive and capacitive touch screens dominate the market today.

To learn more about the different types of touch screens, have a look at this article on our blog. If you’re considering buying a touch screen for your project, you need to know the key differences between the options manufacturers show you. Since capacitive and resistive touch screens are the most popular solutions on the market rights now and are used throughout the electronics industry, you’re likely to end up choosing between them. In this article, we zoom in on the key differences between capacitive and resistive touch screens you should know when choosing the right technology for your project.

Resistive touch screen

What is a resistive touch screen? A resistive touch screen monitor is composed of a glass panel and a film screen, which are both covered with a thin metallic layer separated by a small gap. When you touch the screen, these two metallic layers meet and thereby create an electrical flow. This change in voltage is what detects the point of contact. The voltages are then converted into X and Y coordinates. These are later sent to the controller. Where is it used? Resistive touch screens find broad use in manufacturing, ATMs and kiosks, or medical devices thanks to their durability. Since in most industries users need to wear gloves when using touch screens, the resistive option is a perfect match as it doesn’t require contact with exposed human skin or a stylus with capacitive capabilities. Moreover, resistive touch screens are more cost-effective and easier to use in challenging environments and industrial contexts. Types of resistive touchscreens Resistive touch screens rely on electrodes that create a uniform voltage across the conductive area. This brings a specific voltage reading when an area of the two layers comes into contact. It’s the type of resistive layout that determines the durability and sensitivity of the monitor. That’s why manufacturers offer several types of resistive touch screens.
  1. 4-wire analog
In this setup, the top and bottom layers both include two electrodes oriented perpendicular to one another. While the electrodes on the top sheet form the positive and negative Y-axis, the electrodes on the bottom create the positive and negative X-axis. Thanks to this electrical-coordinate setup, the device can sense the coordinates where once these two layers come into contact.
  1. 5-wire analog
The 5-wire analog setup includes four electrodes located at every corner of the bottom layer, with 4 wires connecting all of these electrodes together. Thanks to a simpler design based on fewer components, the circuit is regarded as more durable than other designs.
  1. 8-wire analog
This is the most sensitive resistive touch screen available. The 8-wire sensing circuit has a similar layout to the 4-wire analog. But you’ll find one difference there – each bar electrode contains two wires. This adds some redundancy into the circuit. However, the touch screen offers excellent durability and helps to avoid the problem of not identifying the location of the user’s finger or stylus accurately.

Advantages of resistive touch screen

●      Good resistance – however, note that since the two layers of material used in resistive touch screens are synthetic (and not natural – for example, made of glass), their surface is more susceptible to wear or scratches than capacitive touch screens. ●      Lower price tag – resistive touch screens are less expensive than capacitive touch screens, which have a more complex technological structure. ●      The versatility of touch – resistive touch screens can react to multiple types of touch. For example, they can register input from gloved or ungloved fingers, but also a fine point of contact as they offer more sensors per inch than capacitive touch screens. ●      Lower sensitivity – a resistive touch screen is less sensitive to touch than a capacitive touch screen. While a high degree of sensitivity to touch can be a good thing, it’s not in environments where accidental stimuli such as liquid spills and splatters can cause them to react unintentionally. That’s why resistive touch screens are widely used in industrial contexts, while the more sensitive capacitive screens are part of consumer products like tablets or smartphones.

Drawbacks of resistive touch screens

●       Lower sensitivity to light touch, ●       The thick top layer results in less clarity for the display.

Capacitive touch screen

What is a capacitive touch screen? Capacitive touch screens were invented almost a decade years before resistive touch screens. Today, they offer high sensitivity and respond immediately when touched even lightly by a human finger. Capacitive screens are made of transparent and conductive materials such as ITO that are coated onto a glass material. So how does a capacitive touch screen work? Contrary to the resistive touch screen, which relies on mechanical pressure applied by a finger or stylus, the capacitive touch screen uses a property of the human body, which is naturally conductive. Where is it used? Capacitive screens are part of most consumer products such as tablets, laptops, and smartphones.

Types of capacitive touch screens

Surface capacitive In this setup, four electrodes are located at each corner of the touch screen. They maintain a level voltage over the whole conductive layer. When a human finger (which is conductive) comes into contact with any part of that screen, it starts a current flow between these electrodes and the finger. The sensors placed under the screen sense the change in voltage and can identify the location of that change. Projected capacitive In a device equipped with a projected capacitive setup, engineers place transparent electrodes along the protective glass coating. They’re located in a matrix formation. The vertical line of electrodes maintains a constant level of current when the user isn’t using the device and the screen is off. The other line (horizontal) is triggered when the user touches the screen and starts a current flow in that area. That matrix formation results in the creation of an electrostatic field in the place where the two lines intersect. This touch screen is one of the most sensitive types as the setup can sense a finger touch even before the user actually makes contact with the screen. That’s why it’s possible to use such a touch screen even when wearing gloves (thin ones).

Advantages of capacitive touch screens

  • Easy and flexible operation – a capacitive touch screen is very sensitive to the input and reacts to it immediately.
  • Multi-touch support – it’s possible to press on an icon and enlarge an image on the screen at the same time.
  • Greater display quality – a capacitive touch screen offers a higher degree of contrast and helps users to see the content displayed on the screen more easily.
  • More accurate input – the potential for errors is greatly reduced as there is little or no leeway for the touch screen to interpret input inaccurately.
  • Enhanced durability – a capacitive touch screen can be more durable than a resistive touch screen. That’s because frequently used areas on a capacitive touch screen usually don’t break down and become unresponsive following heavy use. Also, when a capacitive touch screen is scratched, pierced, or cracked, it will still continue to operate. The same isn’t true for a resistive touch screen, which usually stops working when its surface is damaged.

Resistive vs. capacitive touch screen

Choosing a resistive touch screen for your project brings you the following advantages:
  • Lower cost,
  • Higher sensor resolution,
  • Reduced possibility of accidental touches,
  • Resistance to elements such as heat and water.
The key benefits of capacitive touch screens include:
  • Greater durability,
  • Excellent quality of images with better contrast and sharpness,
  • Support for multi-touch sensing,
  • Reliability (functions even if the screen is damaged)
  • More sensitivity to light touch.
The choice to use a capacitive or resistive touchscreen depends on the unique demands of your application. We hope that this guide helps you choose between these two touch screen types easier. If you need more advice, please get in touch with us. Our consultants are experienced in providing advice to clients operating in the strictest industries such as medical, defense, and military.

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