Wet Capacitive Stylus Pen
Stylus pens are pen-shaped devices that can interact with touch-screen technology such as smartphones. This allows actions such as tapping, swiping, drawing, and other touch-screen interactions to be performed with pen-like precision.
However, stylus pens are quite expensive, despite the technology behind it being relatively simple. This Instructable will show you how you can make your own wet capacitive stylus pen.
Supplies
3D Printer (PETG)
AAA Battery
Aluminum Foil
Cotton Bud Stick
Masking Tape
Scissors
3D Printing Parts
3D-print the parts from the stl files. Referring to the image, these parts are the tip holder (red), battery holder (yellow), and cap (green).
Preparing the Tip
Cut the cotton bud stick in half down the middle. The resulting piece will be referred to as the pen tip. The pen tip has two ends: a cotton end and a stick end.
Wrap the stem of the tip in aluminum foil. Make sure that the stick end is covered, and that the foil is touching the cotton of the cotton end. Do not wrap the cotton end.
Apply masking tape to the stem to make the foil stable. Do not apply tape to the stick end.
Assembling the Tip Half
The tip holder has two ends with a cylindrical hole through it, a wide end and a tip end. Insert the pen tip (pink in image) in the tip holder (red in image) so that the pen tip's cotton end is sticking out of the tip holder's tip end. The resulting piece is called the tip half.
Inserting the Battery
The battery holder (yellow in image) is a hollow cylinder with a wide hole and a small hole. Insert the AAA battery (orange in image) into the battery holder through the wide hole all the way to the other end, making sure that the battery's positive cathode is snugly fit in the small hole of the battery holder.
Shutting the Battery In
The cap (green in image) is a hollow cylinder with a hole on one end and a closed face on the other end. Insert the cap into the battery holder with the cap's open end facing the battery and the closed end facing outwards. Tape the cap shut. The resulting piece is called the battery half.
Connecting the Two Halves
Attach the wide end of the tip half and the battery end of the battery half together with masking tape.
Using the Pen
That's it. You have fully created the stylus pen. Whenever you need to use the stylus pen, the cotton tip needs to be moist for the stylus pen to work. You may dip the pen's tip in water before every session of using the pen.