Chemistry Solutions

“Chemistry is a science of the invisible.” This is a statement I often use with my students when they reflect on the difficulty of my course. Having taught both regular and honors chemistry for the past six years at an inner-city school in Los Angeles, one thing has truly stood out to me: In order to learn, my students need to see and experience.

Explaining that temperature is a measure of the average kinetic energy of particles, or that at higher temperatures molecules will move faster while at lower temperatures they move slower — these statements mean nothing to my students. Yet, if I show them how a drop of food coloring diffuses faster in a beaker of hot water versus cold water, suddenly it all makes sense.

Whether using demonstrations, laboratory experiments, or pictures from a textbook, my goal is to translate the abstract concepts of chemistry into something more tangible for my students: to bring the topics they learn into a more accessible space. I often find myself telling stories and using analogies, heavily relying on the word imagine. “Imagine that I, in the front of the room, am the nucleus,” I might say, “and you students, sitting at your desks, are the electrons.” Such stories have provided an entry point for class discussion about topics of a conceptual nature, like atomic structure and why patterns in ionization energy can be found on the periodic table.

For some students, imagining is more than enough, but for others, as soon as they hear the word “imagine,” I’ve already lost them. Relying on a student’s ability to imagine and visualize something they have never seen before can feel like an impossible task. But what if I didn’t have to? What if my students could hold actual objects representing atoms and molecules and see how and why they go together the way they do? This is how my journey into the world of 3D printing began.

Technology is a word that can trigger mixed opinions, especially among educators. I am someone who embraces a lot of technologies, but I believe that it isn’t the technology in the classroom that makes our lessons better, but rather, how we actually use it. I don’t think technology should replace chemical demonstrations or laboratory experiments performed by students, but I believe it can be used to enhance them and bridge the gaps between what students see, what we think they see, and what we want them to see. As 3D printing technology has become more popular and accessible, I have paid more attention to it, and I’ve recently begun to recognize its potential for a variety of uses. I now think of a 3D printer as more than just a machine — rather, it is an opportunity.

My motivation

My journey into 3D printing began when I realized that my students needed more than the simple tool (Figure 1) that I had been using to help them learn the rules for writing chemical formulas.

This tool, a simple paper grid, provided a lot of value for my students in the past. With all positive ions being written in the left-hand column, the grid helps them to learn and identify which ion should be listed first when writing the chemical formula for an ionic compound. By including the ion charges in the grid, I prompted students to try to figure out how charge affects the number of each ion type needed to form the neutral compound. Most importantly, the students were learning to recognize and analyze patterns as they began to learn the language of chemistry.

This paper grid worked great for many of my students, but several students needed something more or different. When brainstorming ways to reinforce or reteach topics to students who were struggling, I knew that relying solely on the grid would not have much benefit for them. I could create a larger grid, and walk them through it, but that wouldn’t create a new learning opportunity, and I would just be repeating the same information they originally struggled with.

On the other side of the spectrum, what about the student who found this too easy and could quickly accomplish the learning task? I could try to increase the challenge by swapping the location of the ions or replacing the ion formulas with names; but again, this approach is more of the same and doesn’t provide an alternative way to think about the process. If my goal was for all students to have a chance to learn, I needed to come up with more options.

Starting with Lego bricks

My first attempt at finding a different way to help students learn about chemical formula writing was to use Lego bricks to represent individual ions. I wrote the names of the ions on the bricks, and students could connect and disconnect them to figure out how various compounds could form. The number of pegs (or holes) was selected to represent the ion charge. Lego bricks were an affordable solution with a small storage footprint. Alternatively, buying a commercially-available kit with pre-labeled pieces for each of my students would have cost me a fortune (and that is without even considering replacement parts). With my homemade solution, a lost Lego brick would be cheap and easy to replace.

In theory, the Lego bricks were well-suited for the task. They allowed students the opportunity to find patterns and to test their own ideas in a low-risk setting. Most students were successful in using the bricks to model chemical compounds and to correctly write the associated chemical formulas.

In practice, though, this method became a large hassle. Due to the smooth surfaces of the Lego bricks, the written labels quickly wore away (Figure 2). Students in my first class of the day could clearly see the labels identifying each piece as a particular ion. But by the end of the day, only smudges of my writing remained. I also tried printing stick-on labels, but those fell off almost as quickly as the written ink faded. Instead of referring to the pieces by the ion written on them, I’d resort to referring to them by color, which often caused more confusion. That meant that if I wanted to use the Lego bricks as I envisioned, I would need to rewrite the labels on most of the pieces before each new class throughout the day. The labeling became tedious, but it felt like one of the compromises I had to make to accomplish my goal.

Progressing to CAD

I had been following the growth of 3D printing for years and, watching how the technology in these machines continually improved, I knew that 3D printers were becoming more available and more user-friendly. Gone were the days of spending hours setting up a 3D printer, constantly tweaking and adjusting the machine, to ensure a good print. Now, the machines work right out of the box; no more tinkering, just printing. I finally decided it was time to buy a 3D printer.

A 3D printer is a type of automated tool that is controlled by coded instructions that are created when a user inputs a three-dimensional design into the proper software package (Figure 3). Computer-Aided Design (CAD) software is the type of software used to create a design in three dimensions. With the growing popularity of 3D printing, the range and scope of CAD software programs have continued to expand, with professional versions gaining ever greater functionality. Meanwhile, consumer versions have also become easier and more user-friendly, such that even elementary and middle schools are incorporating these software programs into student learning.

Before I started 3D printing, I had zero experience with using CAD. Though some teachers or students may be interested in exploring one of the many CAD programs that are freely available for teachers and students, CAD design skills are not a requirement to be able to use a 3D printer. There are websites such as Printables, Maker World, and Thingiverse, where users generously share their own 3D designs for other people to freely download and use. When I first found these websites, I was surprised to find that many of these creations are even related to teaching chemistry! Before attempting any designing myself, I tried out my 3D printer by downloading some of the shared design files, like Polyatomic Ion Dice

(Figure 4), because I’d be able to print and immediately use them in my classroom. Following instructions that I found online, I copied the downloaded design file into a slicer program (see Figure 3) and then transferred the converted file to the printer

It was exciting to see all the useful designs people had shared, but I knew that if I continued using only other peoples’ work, it wouldn’t scratch that “itch” of creating something myself. When I was ready to try creating my own designs, I looked online for a free, highly-rated CAD software program that was easy to use — and then I just went for it. After downloading the software and watching a couple YouTube tutorials, I began. Remembering the general design of a product I’d previously seen, I first sketched out shapes and dimensions on paper, and was soon able to recreate the sketch on the computer (Figure 5) using the free-for-educational-use program called Fusion360. Once I was happy with the basic look and the design of the pieces, I gave them depth (taking the design from 2D to 3D) and added embossed text on the pieces for clear labeling.

When my design was ready, I exported it into a slicer program to translate the design into specific printing directions for the 3D printer. Most slicer programs have a user interface that shows a virtual image of the build plate (the surface on the 3D printer where the print will be created) and the imported design pieces can be arranged and duplicated within the printable area (Figure 6a). This is also where colors can be chosen, if the 3D printer has that capability. The interface typically displays information such as estimates for printing time, material use, printing cost and other more technical data.

As one of my original criteria for this project was that it had to be inexpensive, I was pleasantly surprised to see the estimated cost of filament (the plastic material that forms the physically-printed object) for my print would be just $1.51 (Figure 6b)! As a comparison, if I go to the Lego website and order six 1"x1" bricks, six 1"x2" bricks, and four 1"x3" bricks, my total is around $1.50 per student. Another advantage is that my 3D printed tiles allow me to avoid the headaches of smudging and having to rewrite all the labels several times throughout the day — instead, I just print once and done! Two hours after sending my creation to the printer, I had a replacement set (Figure 7) for my Lego ions — and these labels were not going to wear off!

I cannot put into words how satisfying it felt to see an idea I had visualized in my head take a physical form. Just like my students, I no longer had to “imagine” what the pieces would look like.

Is there room for improvement? Of course. But that is part of the beauty of a 3D printer. I don’t have to locate a catalog, and then search to find just what I need. I don’t have to settle or compromise on a lesser product just to save a little money. If I don’t like the result, I can simply change the design and reprint until I am happy with it. The only limit now is my own imagination.

What else can I make?

With the confidence I gained from this project, I began to look at my classroom from a different perspective. Instead of relying on the next budget cycle to buy materials, I wanted to see what equipment I could design and print myself. At first, I didn’t think a 3D printer could fit that niche, as I can’t replace glass beakers with a 3D print, nor can I print the chemicals. However, once my students began to do their titrations, I had an idea.

Currently, when my students set up their burettes, they use a very bulky, all-metal clamp. While it gets the job done, I noticed that the teacher next door used some sleek Delrin clamps that were imported from the UK years ago. The school had originally purchased plenty of extras, but over time the clamps broke, and there are no longer enough for me to use in my classes. So, my next project began! I asked to borrow one of the broken clamps, took some measurements, and drew up a design on CAD.

After printing, I found that my first design wasn’t perfect…and neither was my second. In fact, it took over 10 attempts just to get a clamp that worked! I learned to be more precise with the dimensions to make sure the clamp would print in the correct size and that the holes for the ring stand were in the correct location. I also began testing the trial prints with a burette and ring stand to verify that the clamp could slide on the stand while having enough friction to stay in place.

This project originally seemed so simple but turned out to be more than I expected. But that’s the beauty of this technology. Being able to make prototypes and get instant feedback to make necessary changes is what made all that effort worth it, to me. Now, when a student breaks a clamp, I can print a replacement that costs me about 60 cents and takes 30 minutes of printer time, rather than paying five dollars to order one and waiting weeks for it to arrive.

That said, I completely understand that a teacher’s time is limited, and that finding the time to design something specific for one’s classroom can seem like a daunting task. While I love to be able to tell my students that I personally created the materials they are using, I have also learned to pick my battles wisely. If a reasonable solution already exists, I am more than happy to use it. But, if I can’t find something that fits my specific needs, I now have the tools and confidence to attempt a design myself.

The 3D printing community is vast, spanning many fields, and teachers who are skilled in 3D design are constantly sharing their work online for free. Even as I gain experience in designing learning materials and supplies for my classroom, I can still rely on the many designs generously shared by others who are more experienced.

At the end of the day, whether it is designing something for my classroom or simply using a model created by someone else, my understanding of what is possible in my classroom has completely shifted. I no longer feel limited by a catalog — but rather, only by my imagination. I do not know exactly what project I will tackle next, but I know I am ready for it. As I go through my lessons and look at the materials needed, my first thought will no longer be “How much will this cost?” but instead, “Can I 3D print this?”

Reflection

My goal is not to convince anyone to go out and buy a 3D printer. As teachers, we are constantly bombarded with the next “big thing,” or a new “one-size fits all” strategy, each assuring us that it will fix our classroom problems. I promise, this is not one of those suggestions. Ultimately, it is not the 3D printer that is teaching my students; it is me! If I didn’t have the 3D printer, my inclination toward manipulatives would not suddenly disappear. I would continue to use beads, Lego bricks, and even model kits (that is, if I could find enough of them), to help me explain these abstract topics to my students. After all, that is what teachers did before 3D printers, and will likely continue to do in the future.

Instead, my goal is to ignite an idea in you. My own motivation to learn and use this technology came from the frustration of having to deal with smudged, broken, or lost Lego bricks. But for others, it may be the need for a custom piece of equipment for a lab setup, or for a physical model of a lattice structure that students can disassemble, or a desire for a tactile graph to help a student who is visually impaired. Meeting multiple needs within a classroom has been, and always will be, something that challenges teachers.

Chemistry is a science of the invisible. We will always have to ask our students to “imagine” what is going on at the atomic or molecular level. But with the continually-evolving technologies available to us, we are no longer limited to relying on students’ innate abilities to visualize, as we now have the power to put the abstract directly in their hands — in whatever form that may be.

I will not say that using a 3D printer is the answer to all these challenges, but it has answered some of them for me. So, I encourage you to take a chance and try out some new technology that may seem a little daunting to you, at first. It may just be worth the effort, as it was for me!

End note

The hardware and software side of 3D printing can feel a bit intimidating at first. However, there are plenty of resources online to help. If you are interested in a deeper look at how these machines actually work, or want advice on how to pick a printer, I highly recommend watching The Beginner 3D Printing Guide I Wish I Had on YouTube by CNC Kitchen. The developers of this resource do a great job at explaining the basics and troubleshooting, without getting too complicated.