Introduction: Make an Accurate Stylus for Touchscreens
Styluses are almost a prerequisite for making detailed sketches or drawings on a tablet or a touch screen device. Unfortunately, accurate styluses are quiet expensive, ranging anywhere from $50 to $100. various alternative are present on the internet but thee are not nearly as accurate as the expensive styluses available on the market nor do they have attractive appearances. Often they require the tip to be moistened with water to make them work. However, in this Instructable, i am going to show you how to make a stylus which is quiet accurate, easy to make and can be put into a variety of cases to change its aesthetics.
Soluble Copper salt (for eg Copper (II) Sulfate or Copper (II) Chloride)
I have also created a YouTube video regarding this process which can be found here; https://youtu.be/EhLEj4Gsk2k
P.S; this is my first Instructable so i apologize for any errors and am open to any advice to make my future Instructables better.
Step 1: Getting and Shaping the Graphite Rod
Your first step would be to get a graphite rod. You could salvage these from ordinary AA batteries, but beware, it could get messy and the chemicals present in the cell aren't good for you and they could cause rashes on your skin, so wear gloves if you plan to salvage the rods. An alternative would be to just buy them. I, personally salvaged them from some old cells.
Next, i used a rotary tool to sand and shape the end of the graphite rod into a point, similar to a pencil's nip.
Why am i using graphite rods, you ask, that is because in the next step, we will be using electrolysis to coat the rods in copper. Graphite is inert so it does not react with the electrolyte and it conducts electricity so the ions in the electrolyte as discharged and the rods are coated with copper.
Step 2: Prepare the Elctrolyte
To coat the graphite rods with copper we need a solution of a copper salt. Any soluble copper salt would work but i am using hydrated Copper (II) Chloride crystals which have a blue color. If they are not hydrated then, it will be a white powder.
Mix the crystals with a flask filled with water, the resulting solution would be of a blue color (if you are using Copper (II) Chloride crystals). The concentration does not matter as it will only affect the discharge of anions (in my case, Chloride ions and Hydroxide ions), while the plating wil be done by the discharge of Copper ions discharged at the cathode.
Be careful with the chemicals as they are toxic and harmful to the environment so dispose them off with care.
Step 3: Electrolyse the Solution
Electrolyse the solution by passing current through it. I used a 12 volt adapter to electrolyse the solution, however, a stronger current would be better. Connect the shaped graphite rod to the negative terminal of the circuit so that the Copper ions are discharged and a layer of copper gets deposited on the rod.
Make sure the rod is immersed in the solution and leave the circuit switched on for some time. The longer the current is passed, the larger amount of copper will be deposited on the graphite rod. In other words, the amount of current passed and the time for which the current is allowed to pass, are both directly proportional to the deposit found on the copper rod.
Step 4: Congratulations, You Have Made Your Very Own Stylus!
That's it! After the electrolysis is done, you should be left with a shaped graphite. You could inert this rod into a casing which you can make out of a piece of wood. However, it is necessary for your hand to be in contact with the copper coating and there should be a path for the charge to flow from your hand till the tip of the stylus (conduction by graphite does not work, a layer of copper s necessary for the conduction of charge).
Here, you can see the stylus in action;