Published: November 2nd, 2018 Last Modified: November 14th, 2018
Some time ago I was pretty obsessed with building a pipetting robot, and to a degree it was a success. However, building it burnt me out pretty good. I will revisit the project and likely rebuild the whole thing to make it simpler and closer to the original plan. I tore down my opentrons clone, and this is all that remains:
Ahh, memories. But let’s not get all nostalgic and wax poetic. One aspect of the original opentrons robot (which has now been corrected, see their OT2) was that the pipetting section used a hand operated pipette strapped to some stepper motors. I was looking for inspiration from the pros to make my own pipetting module, so I got my grubby little paws on a Biomek P1000 module to tear down. Take a look, it’s a rare treat to see how a part of a 100,000$+ machine is made!
Before we get started, I just wanted to link to another fellow pipetting robot aficionado who is working on their own implementation of pipetting robot software, His Github: Robots by DerAndere His Blog: PipetbotA8. He wants to convert commonly available 3D printers into pipetting robots, awesome! Always a pleasure to meet others who are passionate about DIY lab hardware/software.
So, what’s a Biomek P1000 module look like?
Oooooh yeah, that’s the stuff. Look at that construction! Machined aluminum body, delrin plastic tip eject, stainless innards. Unfortunately for me, when I purchased it I had no idea that there were no motors in the module itself, that’s all housed in the robot arm. Oh well, still lots to see.
Two screws and you get a closer look into the tip eject mechanism, just a delrin cylinder wrapped around the stainless shaft. That little stainless tab connects to the plunger which is actuated by the robot arm.
See that little spring? That’s what does the tip ejecting. The pins connect to a small circuit board to basically tell the robot arm what type of module is connected. The larger stainless circle in the middle is where the piston of the pipette is actuated, again by a motor in the robot arm. Let’s take off the delrin cylinder:
Beautiful, just beautiful. Here’s where the disassembly gets a bit trickier, clearly the end user was never meant to go this deep, need a few different sir clip pliers.
And that’s basically it! Conceptually there isn’t much to a pipetting module, but the devil is in the details. The bore of that stainless cylinder is SMOOTH, perfectly machined. The o ring on the piston is likely some exotic material. No cheap parts to be seen. Not a surprise though, considering a new module would cost…what…3,000 – 5,000$? More? Hope you enjoyed, won’t be too long before I revisit building my own!