Pen Prototype Obstacle Course: Spring vs. Squeeze

David HookCircuit Scribe News

two different Circuit Scribe pen prototypes, one squeezable and one spring loaded

Here at Circuit Scribe we’re always striving to improve our silver conductive ink pens. Recently we released a video that gives a behind-the-scenes view of our pen prototype testing process. We have two new conductive ink pen designs and both administer ink in their own ways. We did an experiment to test their effectiveness on a variety of materials, and we used the scientific method to “draw” conclusions from our tests!

The Pens

The top pen (spring) is a spring loaded pen that uses the pressure of the spring to provide a constant flow of uniform ink. On the other hand, the bottom (squeeze) pen acts as more of a paint pen with a squeezable handle to regulate ink flow. The harder you squeeze, the more ink comes out! Both pens are also using an ink with a higher concentration of silver, which increases conductivity.

The Materials

The first material we tried drawing on was a PCB or printed circuit board. For such a smooth surface we were fully expecting the squeeze pen to shine here. However, we were pleasantly surprised with the effectiveness of the spring pen. The squeeze pen had to be squeezed pretty hard to lay enough ink down, which is evident by looking at the varying line thickness.

WINNER: Spring

Next up is just normal construction paper, and this test went as you’d expect. They both performed great! The spring pen kept a beautifully even line width and flow. The squeeze pen allowed for a more dynamic line weight. This one really comes down to personal preference.

WINNER: Tie

Our next material is wood and we didn’t really know what to expect with this one, although we had a hunch it would be similar to paper for obvious reasons. Our hunch was correct! The spring pen continued to lay smooth, uniform lines while the squeeze pen was able to really lay on a thick layer of ink with ease!

WINNER: Tie

The fourth material we tested our pens on was a piece of plastic. Beforehand, we didn’t expect either pen to perform on such a slick and unforgiving surface. The spring pen continued to impress and laid down ink as if the plastic was another piece of paper. The squeeze pen had a little trouble in the beginning, but once you squeeze hard enough you can get coverage on pretty much anything. In the end, the spring pen required a lot less effort for a very smooth line.

WINNER: Spring

Our final material is a colored paper with two long pieces of tape. The spring pen had trouble crossing the rough terrain, but much like a dune buggy, the squeeze pen was unfazed with the shifting surface. There was a clear winner here!

WINNER: Squeeze

After our rigorous testing, we can conclude that each pen has its pros and cons depending on your preferences and materials you expect to use. Personally, I prefer the spring pen for its across-the-board performance. It really took every material it faced in stride. The squeeze pen had its shining moments, but it just fell short for a) how often we had to redo lines and b) how hard you have to squeeze to make it work on slicker material.

OVERALL WINNER: Spring

We hope to keep experimenting, especially as there has been a fair amount of interest for conductive ink pens that can be used to write on walls and on multimedia surfaces for craft projects that move and buzz and light up.