Create Yor Own Capacitive Stylus for Smartphones / Tablets

      Most smartphones and tablet have capacitive touchscreens. This is an impressive bit of technology and it has insipired a wide variety of accessories. One of these is the capacitive stylus. But you dont need to spend alot of money on a commercial stylus when you can make one for free out of every day items. In this project, I am going to share with you a few of may favorite design for a DIY( Do it yourself) capacitive stylus.

Step 1 - Background Information

      In general, capacitive touch screens work by using an array of sensors to monitor the electrostatic field round the screen. When your finger touch the screen, it change the electrical capacitance of that portion of the screen. The microprocessor captures, filters, and analyzes the data. Then it calculates where the touch occured. When a stylus is used, the same principles apply. The only difference is that the stylus is acting as a conductor to transmit the electrical charge between your hand and the phone. In order to function properly, a capacitive stylus must meet several criteria.

• A conductive surface : It must be able to conduct an electrical charge between your hand and the screen. if the materials is too resistive or if the distance between your hand and the screen is too great, the signal reaching the screen may be too weak to be detected.
• A relatively flat end : Having a flat tip ensure that the whole face can get close enough surface area to  be detected.
• At least 1/4 inch wide : When filtering data, the processor ignores areas that are significantly smaller than a human finger tip. This helps avoid unintentional activation. Having stylus that is about 1/4 inch wide will ensure that there is enough surface area to be detected.
• A smooth surface : This will ensure that you dont stracth up your screen

Following these criteria, you can find a wide variety of common items that can be used to activate a capacitive touch screen. Here are the most effective design for a DIY capacitive stylus.

Step 2 - Sponge Stylus

      Probably the most interesting material that can be used to activate a capacitive touch screen is a sponge. But a sponge is a bit too flexible to make an effective stylus as it is. To fix this, the easiest thing to do is to insert the sponge into a metal pen barrel or other metal tube. This gives it shape and makes it a lot easier to work with.

• Cut off a strip of sponge that is about 1/2 inch wide and about 3 inches long. 
• Pinch the end of the sponge and twist it into the barrel until you have 1/2-1 inch sticking out the end. 
• Make sure that the sponge is deep enough that it makes good contact with the metal housing. 
• Then trim the tip of the sponge with a pair of scissors and round it off. 

The only problem with using a sponge as a stylus is that it will not work if it is completely dried out. The water in the sponge helps conduct the charge. So periodically you need to rewet the sponge. It doesn't need to be soaked, just moist enough that the sponge is flexible.

Step 3 - Try It !

      After you sure that you have follow these instruction, try it to your smartphone or tablet. If you read the instruction properly, i am sure it works. But feel free to ask if you found a problem by comment this article.