Intro: Jake the Dog, Are You an Ipad Pen Substitute?
As a scientist and an artist, I try to combine art and science as always. I discover the following phenomena.
By chance I was playing around with my previous clay sculpture with acrylic paint and my ipad at the sametime. My ipad react to my D.I.Y. sculpture of Jake (from Adventure Time). Is my ipad broken? Or Jake really has some superpowers? Jake Jake Jake!!
This instructable aims at deciphering this mystery in a scientific way, and applying the experimental foundlings to a made gadget hack (sort of)--- a slick looking D.I.Y. touchpad pen. And hopefully inspire you to craft your own touch screen pen substitute.
If you are only interested in the making of the D.I.Y. pen itself, free feel to jump to the last step. The last step: Analysis & Application focus on how to make the ipad pen substitute.
Hang tight and Enjoy!!
Step 1: Remark on Touch Screen (Mainly for Those Who Is Not Sure What It Is…)
Nowadays, Touch pad is the most common input device in most Android and iOS device or laptops. But how does it work?
The answer is CAPACITOR. There is a squad of capacitor below your touch screen. Capacitors are common in electronics even before touch screen. Some time see in microphones and radio, capacitor composes of two metal sheets held close but not touching each other (sometimes with plastic sandwiched in between). When a capacitor is inserted in a circuit, there is a particular quantity can be measured, physicists and engineers like to call Capacitance (just a fancy name, no big deal). Like your weight varies depending on your mass and the gravity of the planet you are on, this capacitance too depends on something. Capacitance depends on the Voltage applied, the length of separation between the metal sheets, or the area of the metal plates Blah Blah Blah.
Most importantly in our case, capacitance change when different material is put between the metal sheets. And BOOM, this is the basis of touch screen. Capacitor reacts to different materials in different magnitude, more vigorous with some materials like water, glycerin, and certain plastic or metal, where as vacuum and air contribute small and almost no effect on capacitors. In other words, capacitor can detect the presence of something rich with water nearby. Please be reminded that our finger is filled with water and blood flowing constantly.
Step 2: The Experiment
As a common trick of artist or sculptors, we like to use aluminum foil to achieve a general shape or armature, then wrap it with air drying modeling clay, in order to save clay and reduce air drying time. You might have heard of using potato chips metal bag and wrap your pen with it. My Hypothesis: Jake has an aluminum core, is this the reason why he can serve the same function? Or the clay and Acrylic paint contribute effect?
I list out some combination of materials, testing which material/ combination of material can account for Jake’s power.
I touched my ipad with the follow 5 materials 3 times each and see the capacitor reacts.
1. Dried Jovi air drying modeling Clay
2. Diamond Aluminum foil core
3. Paper coated with acrylic paint
4. Aluminum core wrapped with Clay
5. Aluminum core wrapped with clay and paint with acrylic
If the ipad respond to any above material, that specific material is capable of canging the capacitance of the capacitor inside ipad…
Step 3: Observations and Results
Dried modeling clay obtains 0% response from ipad. (0 out of 3)
The aluminum foil used obtains 100 % response from ipad. (3 out of 3)
Acrylic painted paper obtains 0% response form ipad.(0 out of 3)
Clay with aluminum core obtains 66.6% response from ipad.(2 out of 3)
Painted clay with aluminum core obtains 66.6% response from ipad.(2 out of 3)
So it seems, clay with aluminum core (with or without paint) is not stable. The fact is that I touched the ipad with 3 sample of aluminum cores cover different thickness of clay, for clay of thickness less than 5mm, is working perfectly. Once the clay covering the aluminum core is too thick (thicker than 5mm), the pen can’t work as ideal as before.
Limitation: The size of my sampling pool is rather small, Data may not be exactly accurate. But considering the small scale of our hypothesis, the data should be sufficient to show some meaningful result. The experiment can be improved with more material and increase number of attempts (more than 3)
Step 4: Analysis & Application
With our experiment data, the aluminum core seems to be the reason why Jake can act as touch pad pen. Where clay and acrylic paint may be barriers reducing the effect of changing the capacitance. And with fabrication of correct thickness, the material can still induce change in capacitance, thus serve as substitute for touch pad pen. And some more experiments I did implies that the larger the aluminum core the greater the effect.
You may ask if the fabrication is reducing the effect, why bother fabricating our D.I.Y. pen. With fabrication, the pen has some new advantages:
- The fabrication can smooth out the pen tip, Aluminum core made with Al foil can be pointy and sharp, Fabrication reducing scratch mark on touch pad.
- It looks a lot more elegant, durable and up for customization than wrapping chips packaging around your pen.
- Free for us to throw in personal flavor and individuality.
- Just a lot more fun D.I.Y. your tools as an artist
What I did is:
A quick an aluminum foil core.
- Wrap a layer of clay around the core Generally smooth out the surface.
- Shape the air drying clay in to Finn
- Let it dry in air (10 hr to 1 day, depending on the size of ur work)
- After the clay harden, Add details and sand it if necessary Be sure the clay around the tip is thin enough, touch it with a touch screen, and check for response. (if its too thick, sand it thinner)
- Clean out the dust from sanding and paint it with what ever color you want!! (water proof paint suggested)
Now I have Jake the dog and Finn the human to a new ipad adventure time!!
Please feel free to ask me anything or leave a comment below.
If you like this piece, you are more than welcome to Fav and vot for me in contest,
THX v. much for your time!!