3D Printed Peristalic Pump Has Impressive Capabilities

[Frank Zhao’s] grandfather has esophageal cancer. Unfortunately for him, it means he’ll be eating through a tube for a while. This involves someone helping him with a big syringe to push a thick food liquid through the tube. [Frank] knew there had to be a better way. While [Frank] was in the hospital in China visiting, he started designing a 3D printed peristaltic pump. It’s what you would expect: a mechanism that massages a loop of plastic tubing to push the contents further down the path.

After he got back to the States he refined his design a bit more and started 3D printing. As it turns out — it works pretty damn well. In the following video he shows it pumping mayonaise — and since it’s peristalic, no priming of the pump required!

He’s entered this project into the Boca Bearings 2015 Innovation Competition, and this is the last month for voting — there’s still time to submit your own project too, but you’ll have to hurry up! We’re of the opinion that someone from the Hackaday Community should win all of these engineering contest.

[Frank Zhao] is no stranger to Hackaday either — a simple search will pull up dozens of his past projects. And like all his work, he shares it freely under the open source license. You can check out the 3D designs for the pump on the OnShape CAD library (will need to sign up for a free account though).

31 thoughts on “3D Printed Peristalic Pump Has Impressive Capabilities

  1. “In the following video he shows it pumping mayonaise”

    He very clearly says he is testing with Alfredo Sauce, which seems considerably less viscous. Not sure if the pump would handle straight mayonnaise.

    Either way, definitely cool.

  2. This seems like a great idea to strap to some sort of nozzle for a paste extruder! The directional nature of the pump could be used for retractions, while the easy control of a DC motor would be simple enough to work with in the firmware. This could turn into a pretty decent pancake bot or something! I think I may just do that actually!

    1. The disadvantage of peristaltic pumps is that the flow rate is a pulse, not evenly continuous. This fact has no impact on food.

      What you could do, and will probably need to anyways… is to use a stepper motor, or motor with encoder feedback, to counter the pulses.

      1. if it’s about counting the revolution or the pulses. I can imagine you putting a micro switch in the wall behind the tube. Whenever one of the 3 bushings (as in your video) rotates pass this position, it would squeeze the tube and push the micro switch/button behind the tube. Micro switches used in pc mice are made to last a few million presses and should be fine.

      2. Have you had fluid pumped into your body? For a year? I have.
        The pulses hurt at first, but you get used to it.

        Still, a peristaltic pump does not need to be pulsed. when designed just right the flow will be continuous. This design with the rollers pressing on a pipe, can be modified to get continuous flow. Imagine a straight pipe and a BIG wheel with lots of rollers. as the wheel is big, the rollers retract from pinching the pipe really slowly and the flow becomes continuous. This proves that it can be done. It can be done much smaller.

        3M probably has a patent on a different trick. Pinch off the output,. fill a reservoir, pinch off the input empty out the reservoir. Simple, but pulsed. Now you modify this: duplicate the reservoir, double the size of the first. Now when the output (of the first one) is pinched you can empty the second one towards the patient. When the input is pinched, you empty the big (first) reservoir into the patient while at the same time refilling the second smaller reservoir.

  3. I found some inkjet printers have sweet little peristaltic pumps in them (Epson from memory), you’d probably want to replace the rubber tube full of old ink before feeding your old folks with it though.

    1. All inkjet printers have this kind of pumps.

      They are used to suck some ink while the printing head is parked, in order to unclog the print nozzles. The debit of this kind of pumps found in printers is very low, since these pumps are used to purge the print head nozzles without draining too much ink.

    1. That design is as bare bones as it gets and I wouldn’t trust any design to not utilize steel ball bearings.

      Anyways, I did look at other designs, but none of them satisfied my requirements, which is to be able to mount a DC motor securely (most of them hosted stepper motors, which makes sense in a lab scenario but not this one), use ball bearings, and also have an outer shell that the tubing is pressed against to ensure a seal.

      Plus, I have a attitude of designing something myself whenever I can, this is how I learn.

    1. I am using soft PVC, because it is clear, and McMaster did explicitly say it is recommended for peristaltic pumps. Semi-clear silicone is also recommended by McMaster. Both are food safe. I do not know which one has a longer life. Sorry, I know that’s the real answer you want but I don’t have numbers to compare, so I just went with clear tubing.

      1. hi, thanks for replying. I was just wondering because I’m interested but having no knowledge about peristaltic pumps I thought they used some exotic unobtanium materials in pumps used for life critical, space etc. devices.

        1. My other half works in a hospital and it seems to be a “medical-grade” silicone tubing but it’s considered a consumable so it is replaced every time which would no-doubt help prevent any likelihood of it wearing out during use.
          I guess anyone designing their own needs to ensure it is relatively trivial to replace the tubing rather than having to strip the entire machine down each time.

  4. we use commercially available peristaltic pumps of similar size in swimming pool instalations pumping hydrochloric acid, or sodium hydrochloride. the teflon bushings pumping the liquids give up the ghost quite fast and need often replacement.

      1. Because how else would they be making money? The in-laws had some swimming pool widget break a while ago, so engineer me decide to look at it / fix it. Turns out it used a plastic locking flange that had so little material in it I am surprised it lasted a year. It is a particular pet peeve of mine.

  5. Anybody succeeded in exporting the design from ONSHAPE? I’ve signed up, I can view the design, but I can’t find the things to click to export the design. The onshape website crashes my web browser every two minutes…

    1. You should be able to see a export button when you right click on a tab at the bottom. Each tab represents one part.

      If you pick a export setting that’s too extreme, Onshape has a bug where it spits out a zero byte file. But the “fine” settings for STL is always pretty good.

      I can’t help you with browser crashes, sorry.

  6. while a diy peristaltic pump is nothing new, I like that Frank is building something to help is grandfather. Applying knowledge and engineering on real world problems should be more appreciated!

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