Capacitive vs. Resistive : TouchScreen Battle !! Which one right for you?

With the slew of touchscreen phones and even touchscreen desktop and laptop monitors coming out almost every week, it is perhaps safe to say that we are at the dawn of a new touchscreen generation. As such, I believe it is important for us to familiarize ourselves with the kinds of touchscreen that are being used in the market today. This is the only way for us to be able to make informed choice when buying our next touchscreen gadget.

There are many touchscreen technologies that are available right now. Some of these include Strain gauge, Optical Imaging and Dispersive Signal panels but the two most popular kinds of touchscreen, especially in cellphones, are:

1. Capacitive
2. Resistive

The other types are also interesting but because Capacitive and Resistive are the two most used and most common types of touchscreen today, I'll center the discussion on them.

First, let's talk about Capacitive Touchscreens.

A capacitive touchscreen panel makes use of an effective insulator such as glass, coated with a transparent conductor like indium tin oxide. Since the human body is likewise a conductor, touching the surface of the screen results in a distortion of the local electrostatic field, measurable as a change in 'capacitance'. Various technologies may be used to determine the location of every touch. The location can be transferred to a computer running a software application or operating system which will calculate how the user's touch relates to the computer software or commands a function.

Here's an illustration courtesy of Rycom Technology showing how Capacitive technology works:


The finger itself conducts electricity with the conductive coated screen


What are the advantages of Capacitive touchscreen technology?

Capacitive technology is ideal for devices that support multi-touch technology. Also, since only distortions in electrostatic field are measured, no pressure is needed to activate the touchscreen (vs. resistive).

What are the disadvantages?

With capacitive, you can't use a non-conducting stylus to make the screen work. You also won't be able to use it with your gloves on.

Some devices that have capacitive touchscreen include:
Apple iPhone, Palm Pre, HTC Hero, LG Arena and Samsung Omnia HD

Now, let's talk about Resistive Touchscreens.

Unlike capacitive, a resistive touchscreen panel is composed of more than 2 layers, the most important of which are the two thin, metallic, electrically conductive layers separated by a very narrow gap. When an object, such as a finger or a stylus, presses down on a point on the panel's conductive outer surface the two metallic layers become connected at that point: the panel then acts as a pair of voltage dividers with connected outputs. This causes a change in the electrical current or a conduction of electricity which is registered as a touch event and sent to the controller or operating system for processing.

Here's an illustration, again, courtesy of Rycom Technology showing how Resistive technology works:


As you can see, pressure on the outer layer makes it touch the inner layer causing conduction of electic current, registered as a touch event


What are the advantages of resistive touchscreen?

With resistive technology, you can use your fingernails and even a stylus to activate the touchscreen. Since pointed objects like a stylus can be used on the screen, touch events on resistive screens are also more accurate compared to finger gestures on capacitive screens because fingers generally have a wider surface area vs. stylus. A major advantage of resistive technology is that you can use it with gloves on - This is important for mechanics, technicians, etc. who are required to always wear gloves at work.

What about the disadvantages?

Very few, if not none, resistive touchscreens support multi-touch feature.

Some devices that have resistive touchscreens include:
Nokia N97, Nokia 5800 XpressMusic, LG Cookie, Sony Ericsson Xperia X1 and X2

There you go. :) Have fun choosing your next touchscreen gadget. :)



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5 comments:

  1. Capacitive touch (like that which is found on the iPhone) is much more responsive to your finger and requires less effort to use than the traditional resistive touch found on Windows Mobile devices. That is why it is popular on many new touch screen platforms. However, that comes with a cost… Capacitive is far less accurate. If you’ve ever wondered why Apple left out handwriting recognition from the iPhone (despite even the original Palm Pilot or Apple’s own Newton supporting this), this is often cited as the biggest reason. You don’t get that single-pixel tapping accuracy that a resistive touch offers. Apple’s UI more than makes up for it, however, by designing the OS with that limitation in mind.

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  2. i like this website. it's very helpful.

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  3. enigma, musta....
    My answer is DEFINITELY the capacitive. Has anyone ever tried using resistive touchscreen on an airplane? good luck on that!

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  4. i have a htc hero, do you know if theres any apps or softwares that i could download to change it to where i can use my finger nail instead of my finger? ive searched all over the internet. theres probably not but i thought it wouldn't hurt to try! thanks!

    Melissa.. MLSSYGOODS@AOL.COM

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  5. i have a question.
    with a resistive touch screen, you need 'pressure' and you can hardly use your finger? i dont get it. :(

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