Step 8: Lessons learned and future work

We dug into this project with essentially zero hands-on expertise with bioprinting, driving stepper motors, driving inkjet cartridges, or even programming Arduino! So naturally, not everything we did was as optimal as it might be. Here's some things we might do different next time:

- Learning how stepper motors work and how to drive them was a really valuable learning experience, but we could have saved ourselves a lot of time and effort by adapting some of the RAMPS (RepRap Arduino MEGA Pololu Shield) technology that has already been well developed for precisely this purpose by the 3D printing community. In particular, the Pololu stepper drivers already have microstepping capability built-in.

- Building your own XY stage for essentially free is great! But we are using these stepper motors for something they were never designed for, and it's starting to show. We are already getting some trouble with the bottom stage skipping occasionally, presumably because we've been resetting the sage by hand too often, which puts a lot of wear on the plastic bits that track the worm gear. It would be easy enough to buy some stepper motors brand-new, lasercut a frame to hold them, add some micro switches for end stops, and code a position reset function in software.

- Once you start sourcing brand new stepper motors, laser cutting a frame, and wiring up RAMPS electronics, why not just start with a 3D printer instead? If we get tired with our current BioPrinter version, that's probably the direction we'll go. Cost would likely go up by an order of magnitude or so though...

- Having a single print head has its own limitations. If we really wanted to do some sort of tissue engineering, we'd love to be able to print multiple cell types, and put some scaffolding material in between. We could potentially put two inkjet cartridges back-to-back. The solution the Big Boys in this field use is syringe pumps. Imagine having several syringe pumps sitting next to the printer, each feeding a different printing material via a thin tube to a needle mounted on the print head. Stay tuned...

Now the elephant in the room... What the heck do you do with your own BioPrinter? I don't think a place like BioCurious will ever compete head-to-head with companies like Organovo in terms of printing human tissues or organs. For one, animal cells take a lot of effort to maintain. Plant cells are much easier to work with though! Don't want to give everything away, but stay tuned for some of our next Instructables!

Meanwhile, here are some ideas:

- Print gradients of nutrients and/or antibiotics on a layer of cells to study combinatorial interactions - or even to select different isolates from an environmental sample.
- Print patterns of growth factors on a layer of eukaryotic cells to study cell differentiation.
- Print two or more microbial species at different distances from each other, to study metabolic interactions.
- Set up a computational problem as a 2D pattern of engineered microbes on an agar plate.
- Study Reaction-Diffusion systems
- Print 3D structures by over-printing layers using the inkjet head. Now you can consider doing all the above in 3D!
- Print cell in a sodium alginate solution, onto a surface soaked in calcium chloride, to build up 3D gel structures (similar to spherification process in Molecular Gastronomy)

- More ideas? Post them in the comments!
cglaw20131 year ago
ZacWolf2 years ago
Reading this Instructable gives me chills! It seems that the Critical Path for most bio-discovery/experimentation is the cost of the equipment. Especially in genetics, where the cost of sequencing machinery has dropped by orders of magnitude, but custom creation of DNA for experimentation (such as using it for data storage) is still cost prohibitive. This sort of tinkering really gives me hope that "printing" DNA may not be as far off as first imagined! Excellent job!!!
schmitta2 years ago
Incredible instructable. Great work guys -- keep it coming !
Matz2 years ago
Great Instructable! For your next version, when you replace your slides, you might want to check out OpenRail, OpenBeam, and MakerSlide as possible alternatives, especially if you want to increase your printing area.