Material Science and Ecological Impact Using 3D Printing Materials

I haven’t exactly been subtle about how sweet 3D print can be…

The various options I’ve seen and imagined have usually focused on the engineering aspects of making. In biology classrooms, I can do a better job of building maker experiences with rich biological connections. Some community conversations have led me to sharing this idea for a project that marries 3D printing and biology is an interesting way.

h/t Drew, Jessica, and Shannon. Also, Topeka Public Schools STEM teachers for a great conversation while I was considering this article – your work impacted this post.


This project could hit lots of standards, but these are the few I had in mind when I wrote this:

Our driving question is important, and is going to mean different things to different people:

“What plastic should we use when 3D printing?”

I would ask the students to begin operationalizing what that question means to them. There are probably going to be two themes in the answers:

  1. What printing materials create the best print products – probably defined by strength.
  2. What printing materials have the fewest negative impacts – probably defined by plastic waste consequences.

I will proceed assuming the first question is the initial focus. If that’s the case, I wouldn’t force any consideration of the second question… it will give us a fun payoff later.

Phase 1: Best Print Products

Students can be given time to create a procedure for stress testing parts printed with different plastics.

What’s important throughout this whole testing process is that you ensure students save every print they make. Broken parts, failed prints, unused replicates… everything they print, they keep!

Phase 2: Matter Cycling

After students complete their analysis of strength, they can return to their driving question. Do they have an answer? If they say ‘strongest is best’, then we can let the conversation move on… to clean-up. What do we do with all this PLA and ABS plastic?

If a particular plastic is best, then we can ask them to think about scale. What happens when everyone starts using it? A big draw for PLA is that it’s not petroleum-based (which is good). The issue still remains of disposal. PLA is compostable, and ABS is recyclable… right?

Students can then read this article from – “What They Don’t Tell You About 3D Printing PLA”. Despite the title, it lays out a good description of what PLA production and disposal looks like. What does it mean for PLA to only be compostable in “industrial settings”? This article from 3D Printing Industry “Is Recycling PLA Really Better Than Composting” describes the various disposal methods of PLA.

This leads into an opportunity for students to learn about matter cycling and home composting. Ideally, they’d create their own compost piles. They can measure moisture and temperature… lots of great science in a compost project.

Phase 3: Solve a Problem

Now that students have some experience with composting and 3D printing plastic, it’s time for them to solve a problem they themselves have made (all their leftover prints)! The students can design their own methods for adding their PLA printed parts to their compost piles. Here are some resources to help:

  • Students can compare the impact of the PLA/PCL blending methods on their originally considered model properties with this peer-reviewed paper

Students could implement a method for adding their plastic to the compost piles, and then collect data for the next month or so. Class could shift focus to other topics while students continue monitoring their projects. The extended time frame could provide the students an opportunity to present the results of a major project around the end of a semester.

These are just some rough ideas I had when I came across the first article. There are basically three steps, and you could approach each in lots of different ways:

  1. Print.
  2. Compost.
  3. Design.

What do you think? Anyone want to try it? I’d love to help/consult with someone who wants to give it a shot.

3D Printing Authentic Fossil Samples

I had some biology students developing a guest lesson on fossils, and we got to thinking about how we could put real fossil examples in the hands of students. Here are our standards:

Sure we can find some fossil examples on Thingiverse, but what we can find are somewhat hard to predict, their organization does not have a scientific basis, and their origin is not always clear (not to mention concerns about the company practices of the owners of the platform). I wanted to look elsewhere for better models provided by organizations more aligned with my professional values.

I found GB3D Type Fossils. Here is who they are and what they do (from their own website):

“The GB3D Type Fossils Online project, funded by JISC, aims to develop a single database of the type specimens, held in British collections, of macrofossil species and subspecies found in the UK, including links to photographs (including ‘anaglyph’ stereo pairs) and a selection of 3D digital models.”

You can search at their home page using appropriate scientific names for the samples you want to find. Check it out:

From the search results you can find actual research samples, linked to their papers and researchers. It comes with high-res photos and 3D scans of the sample.

3D scans are still pretty finicky, so you’ll want to groom the model before you go to print it. We’re going to bounce back and forth between a couple programs to get this bryozoan ready to print:

  • Meshmixer – Processing software from Autodesk, for fixing model errors and generating supports.
    • Free, but not open source.
  • Slic3r – Slicing software for converting models to 3D printer instructions.
    • Free and open source

Step 1: Make the scan a “solid” – Meshmixer

This will take the crazy scans you get from researchers and forcibly make it something slicing software can interpret.

  • “Import” the .obj that you download from GB3D and extract from the ZIP file.
  • “Transform” the model and drag it up and over so it’s positioned in the middle of your build plate.
  • “Make Solid” and let the computer fix this nonsense.
  • “Export” the model as an .stl

Step 2: Orient the model – Slic3r

This will take your (probably wonky) model and orient it for printing. You might be able to skip this step, if you don’t need to rotate your model. This example needs it, because the flat bottom is not actually aligned with the build plate.

  • “Add” your recently exported .stl of the fossil.
  • Select the fossil model, and click “Rotate to Face” (see below)
  • Click on something that should be the bottom.
    • Even apparently flat surfaces are probably not truly flat. We need to fix this, so don’t be fooled.
  • “Export STL” and you can overwrite your previous .stl with this new file.

Step 3: Perfect the bottom – Meshmixer

This will smooth the rough bottom surface, so our print will actually adhere to the build plate.

  • “Import” the recently updated .stl file of the fossil from Slic3r.
  • Use “Plane Cut” to chop off the very bottom surface (see below)
  • OPTIONAL – If your fossil requires supports, now is the time to add them.
    • Find Meshmixer supports under “Analyze” → “Overhangs”
  • “Export” the finalized model as an .stl

Step 4: Print – Slic3r (or whatever)

The model is done and you can now print using whatever your preferred printing workflow may be. Slic3r does a good job creating Gcode, and a simple extension can convert it to .x3g if your printer requires that.

Don’t forget OctoPrint – an awesome Raspberry pi printing option

From here you can go give your students fossils to analyze! I imagine asking them to paint the samples to highlight what they think they are seeing could be cool. They could also color-code homologies across multiple fossil types.

How else could you use fossils in class? Share your ideas and photos of your awesome prints!

Was in my Classroom: A Biotechnology Program

I got some really great news recently: some of my biotech students from last year are insisting that the program live beyond my tenure. The students who persist are not your typical advanced science participants (both were new last year and had zero science training beyond their graduation-required science courses). They found a sense of purpose and belonging and I’m really moved that they are exercising their agency. The program is more than the principle investigator.

My Report: By Michael Ralph

They have a new sponsor and the question has turned again to, “What the heck is the Biotech program at Olathe East?” This is an open letter to the new sponsor, and I share it here so my debrief can be of value to anyone else considering something weird. Here we go.


What Would Professionals Do?

Keystone Habit #1: BE a Research Lab

We did everything like a grant-funded university research lab. Every question was, “How do professionals do it? We will do it like that.” There was no pre-planned curriculum. There were no tests. There were no points. One thing matters: the question. Can we get methanotrophs out of there? The joke gets made frequently that, “[some biology topic] could be a whole course right there!” Ha ha, but it won’t be… Well, this was that course. From day one, I assigned new students to help me address my question. Train on taking water samples, learn to cell stain, build me a sensor… we’ve got stuff to do. When they needed chemistry to mix the Nitrate Mineral Medium 2014 (NMM14), we’d stop and learn it. When pressure gradients were needed to understand a sampling design, we’d learn that too. Professionals have meetings, so we had them. Professionals present at conferences, so we did that. Professionals do outreach, so it’s on the calendar. WWPD, all day every day.

When students started to become more comfortable in the space, they invariably start having ideas and asking questions. We’d follow the postdoc model and let them split their time. My veterans of several years would have the freedom and authority to oversee an entire research team. Students specialized and began to follow their own interests, while still having responsibilities to the original investigation.

Take home recommendation: craft your own driving question. It’s got to be really good. Then focus on nothing else.


Only one thing I can’t use… a credit card.


Keystone Habit #2: We’re Cheap

Necessity is the driver of innovation. We performed robust biogeochemical analysis with scraps and pennies. Only 1 of our 5 years did we have any dedicated budget (it was in the middle and it went away again). Scrap lumber from theater, scrap electrical from district contractors, spare keyboards from IT, waste planters from horticulture… being efficient scrappers was so ingrained in everyone’s attitude that when we did the final tear down I had to throw many of the items away myself because students could not be convinced anything was trash.

Big flashy equipment is a crutch when students don’t yet understand the fundamental concepts they’re investigating. When you really commit to finding a way, it’s amazing what you can make work. 3D print parts rather than buy them. Leftover dry ice in shipping materials. Creating long-term storage cultures in the freezer rather than reordering. Mixing your own bacterial media instead of pre-made. It makes the program cost-effective and the students see more of what goes into the project. They understand the bacterial medium because they had to make it. Sterilization makes sense because it was a total pain to sterilize that equipment.

Take home recommendation: fancy equipment and protocols are not the point. They take great pictures, but they aren’t science. This stuff is hard and making any arbitrary technique the course focus will obscure what it actually means to learn in a biological research space.


Anyone can help those who can already help themselves.

Keystone Habit #3: We’re Inclusive

A good driving question is both accessible and complex. That means nobody who hasn’t intentionally trained in that area will have strong background knowledge on how to investigate it. The end result is who cares what level of math they’re in?!? AP Biology students know as much about methanotrophy as freshman (in every practical sense). We have a serious exclusion problem in high school science; don’t be a part of that problem. Any student… ANY STUDENT… who is interested and willing to join should be welcomed. I have a litany of “not science students” in my alumni base who made powerful contributions to our project. I had freshman leading research teams, remedial students self-identifying as mycologists, and more.

There are plenty of biotech programs out there, collegiate and high school. They are picturesque spaces with students in lab coats wearing goggles staring intently at test tubes. They burn through budgets and look great on resumes. The problem with these programs is the course has become about the techniques. Put your hands on an electrophoresis chamber. Check. Touch a thermocycler. Check. These are Petri dishes. Moving on. Biotechnology in the industry sense is a highly derivative field that requires expertise in more than a half dozen disciplines. Our high school students are not that. Indeed, the few who can be have boatloads of options for how to pursue enrichment. The world doesn’t really need an expensive, esoteric course to serve the 1 or 2 students a year ready for that kind of work.

Take home recommendation: Get Them All Involved. I’m not saying tolerate distraction, destruction or ineffective behaviors. What I am saying is it’s easy to quibble with the all the other programs about that top 3% of students who will spin gold in any classroom. Instead, find all the other students who just want to do something meaningful… and give them some sweet science to explore.


There’s so much more I think and want to say, but ultimately this post is prompted by students. Let the program be theirs. For that matter let it be yours too. Don’t investigate methanotrophs, find your own thing. Let the students help you decide what that might be. Talk with others in the field when you need help. The putting greens are pleasant, but well-traveled. Get out in the weeds a bit.


And post about it. A very proud former investigator will be following your progress.

Discuss Research

Any teacher with a year or two of experience has had one of those conversations. You have six things to get done before you leave for the evening and you’re hustling to catch someone before they’ve left too. You pass a colleague in the hallway and they make a comment that catches you just right. You pause and give a remark from your own experience that seems to resonate with them too. In no time flat you’re both an hour into a conversation that is reshaping your practice. It happens to everyone, and often they are the most disruptive and creative milestones in a career.


We’re doing a business… without an office?!?!? (image from Shutterstock)


Those discussions never seem to happen during a scheduled workshop. A basic think-pair-share-move on doesn’t produce that kind of dialogue. Deadlines get missed… dinner gets postponed… but that time is so remarkably valuable and satisfying that it never seems like anyone is willing to walk away from them when they’re happening. Let’s get more of that.

Our brand new podcast. It’s great. Check it out!

I launched a podcast recently (Two Pint PLC) and Woodruff and I have been talking about how to get more folks engaged. We’ve had multiple people give some excellent perspectives on some of our discussions and I have been really sad that those contributions aren’t available for everyone. KABTers have done meetups periodically, so what do you all think about trying to find a way to create a forum to continue those conversations as they happen organically. We’ve got the Facebook page, but that page has so much other stuff going on that I don’t know it’s the best place for lengthier (I hope) dialogue. This blog hasn’t engendered that level of casual back and forth… So ideas? How might we get something more akin to a forum going to discuss research?

AP Biology – Layered, Mastery Assessments

Eleven months ago I wrote a letter to my AP Biology students about stumbling in my efforts to include more learners in my AP Biology program. I was deeply conflicted in deciding how to proceed from our scores; student morale was as good as it had ever been and enrollment was up but their scores were the lowest of my career.


This was my last year teaching AP Biology and the changes in my methods continued. Enrollment this year tripled last year’s and early numbers showed them on the rise again next year (had I remained to teach again). Since my commitment to inclusiveness over scores two and a half years ago, I have lost ZERO students to the scythe of early year panic drops. I had groups of students approaching me, a remarkable number of which were future enrollees whom I had yet to even teach, looking for lab placements and enrichment experiences to get more involved in science. Students believed they could biology. I am happy to say I built the environment I sought for my AP program.


Scores are not out yet, but I did another overhaul of my assessment system which I think is worth sharing. When I was brute-forcing my student success I used textbook question banks and regular weekend quizzes to ensure my handful of students did A LOT of testing and their AP scores were very strong. I transitioned last year to only assess by asking students to write what they know and we focused their analysis on what they could add over multiple attempts. Every student knew something about photosynthesis and every student could know something more than what they did each time. Nobody felt useless or stumped, because even if they knew they “weren’t there yet” they could work from what they did know and focus on filling their gaps and fixing their misconceptions.


The shortcoming in this system was the lack of an anchor for the students in evaluating what they know against what the College Board asks them to know. My students were surprised in May because I had told them they had mastered a topic, but my judgement was imperfect and being able to talk about what they know is meaningfully different from solving problems set within a schema… or more often at an intersection between multiple large networks of ideas. I must give my students practice working from what they know while they experience problem solving in ways I had failed to maintain during my transition last year.

Students will feel great about not knowing that much about HW…

So this year I changed my assessment perspective. I still need to hook students on our culture of knowing things, and you must know things to solve problems. For those reasons my first semester changed very little. I made a re-commitment to inquiry and lab experience, but my knowledge assessment suite was only sharpened and refined.


Second semester, however, we were ready to be dangerous. We knew about the world of molecular biology, so from day one we worked to address problems. In January I said, “Muscular dystrophy… what’s the deal with that?” We actually had about half an hour of productive discussion regarding what we did know (I got yet another reminder that students are not blank slates!), but then I handed them our first formal assessment. It had a full page of background information pulled from expert sources and a deceptively simple prompt. They said we don’t know this…

Hint: You’ll need more than one page to fully answer this prompt.

Great! What do you need to know to be able to solve this problem? We made a list. Our work was filling the gaps they needed to address the problem. Once the list was all crossed off, we attempted the problem. After several attempts, they were ready for more. “AIDS resistance… how’s that possible?” Away we went again.

CCR5-Delta32: Enzymes and shapes… It’s always enzymes and shapes, bros.

The top level of work changed each time they attempted the assessment, but usually only in small ways that ensured they focused on the ideas rather than the test itself. Every student could still know something, but now there was a much more concrete framework for their trajectory of development. It was challenging to writing milestone assessments that appropriately built student understanding in ways that actually conferred success on the summative assessments… but I think I hit the mark more often than not. In January students needed 3+ attempts per assessment to finally bank all levels, but by April I did have students banking things first try.

Understanding this was only part of the first level… sweet baby James we loved cell signaling this year.

Logistically, I provided students with the concepts level and the background reading at the start. The synthesis was brand new each of the first several attempts, but as a class they found it more comfortable to only attempt concepts the first time around so they could have more time to write and revise without the time crunch of getting both things done while both phases were unfamiliar. If students banked all levels of the knowledge assessments/driving problems, they were automatically awarded credit for all formative milestones (but not visa versa). This took a lot of pressure off students who wanted to focus on growth during the unit to be ready to crush at the end, and eliminated the redundancy of going back to do in part something they’d already demonstrated they could do in full. I was surprised to see an even divide of the class, some preferred to bank every chapter first and some wanted to just work the big problems.

An early biochem milestone assessment.

A milestone assessment from sometime in March.

I don’t think these assessments are perfect, and I’m posting them warts and all. What matters is that old concepts continue to be explicitly assessed in later topics (see biochem stuff in like… every single assessment). Here they are. Many need copy editing and revision from how they were delivered this year because they were new. Take, modify, use and share in good health.


Students need opportunities to show what they know. Deficit grading will disenfranchise too many students, especially in AP classes. To remain successful we have to find ways to provide layered assessments that are accessible to students at many points on the learning trajectory while still building toward the robust understanding expected by AP exams. Philosophically, I am really liking the path I’ve been on. Perhaps some of you will walk this same direction and push even further down the road.


I’ll update this post in July when the scores are released.