Ender3 3D Printer Kit Transformed into Open, Programmable Syringe Pump Set

Video 1 – Showcase of the Ender3 syringe pump system. Adapted from Video 3 of the preprint (2.5x original speed).

 

Background

Syringe pumps are widely used for research purposes [1-5], but those commercially available are costly and provide little opportunity for automation [6]. Thus, many groups turned to building their own syringe pumps. These “Do It Yourself” (DIY) syringe pumps typically consist of a 3D-printed frame, stepper motors, and store-bought fixings such as screws and nuts. Also, they are usually driven by common controller boards and associated software, such as Arduino and Raspberry Pi [7,8].

While current DIY syringe pumps work correctly, building and programming them requires sourcing the parts and prior knowledge in programming. These factors limit their use by groups specialised in research fields such as Biology and Chemistry.

The advent of 3D printing resulted in the availability of common 3D printers at relatively low prices, enabling users to manufacture parts and devices otherwise only available commercially [9].

Ironically, a standard 3D printer contains all the components required to build a set of syringe pumps, including stepper motors, a motherboard, a power supply, and linear motion systems. Also, the open software used to control 3D printers can be exploited for controlling the pumps, avoiding the need to program the pumps from scratch.

In this preprint, Baas and Saggiomo repurpose one of the cheapest 3D printers available in the market, the Creality Ender3, to build and control a set of three syringe pumps for under 200€.

 

Key findings

1) Hardware description, design files, and assembly guide

Most parts required to build the syringe pumps are included in the printer, and the remaining are relatively inexpensive and usually available at common hardware stores. Moreover, online stores specialised in selling 3D printers often sell these parts, enabling the user to buy all of the components in a single purchase and have them delivered locally. The pump model includes some 3D-printed components, for which the description and design files are provided in a ready-to-print format, as well as suggested printing settings and tips. Thus, the 3D printer can first be assembled to print those components, and then repurposed to build the pumps. The preprint also includes a complete list of the materials required and the corresponding budget.

Importantly, the authors provide a detailed step-by-step assembly guide and another guide describing ways to control the pumps. This last task can be achieved using freely available direct-control software. For example, Octoprint (www.octoprint.org) allows the user to control the pumps remotely. Another method involves writing simple text commands that can be compiled in a text file and delivered to the pumps using a micro-SD card, allowing the user to control the pumps using the 3D printer’s interface. A detailed guide on how to write such text files is also provided in the manuscript.

 

 

2) Validation and characterisation

The authors address possible functional failures and explain how these were minimised by design. Furthermore, they test important aspects, such as the precision and stability of the pumps’ output. For example, 10 µL of water were dispensed 10 times using a 1 mL syringe, and the output volume was measured using a high-precision analytical scale. The average error calculated was well in the range of the scale’s own associated error, highlighting the pumps’ high precision. Nonetheless, the authors explain how fluid dispensing precision can be optimised by fine tuning the pumps. Flow stability, which is particularly important in microfluidics applications, was tested by delivering two liquids using two separate channels that merge into a third channel containing its own flow. Measurements and video evidence provided in the preprint show that the flow rate is barely disturbed at the interface between the liquids (Video 2).

Video 2 – Flow stability test. Two differently coloured liquids are pumped at a controlled rate through two separate channels that merge into a third channel containing a reference flow. A few moments after the flows are established, a steady state is achieved, and the flows’ direction and velocity remain unchanged. Adapted from Video 2 of the preprint (2.65x original speed.

 

Why I think this work is important

The work developed in this preprint brings DIY syringe pumps even closer to inexperienced users by overcoming crucial limitations associated with building and controlling such devices. The pumps’ design is ingenious because they are inexpensive, and their assembly is fast, simple, and uses easily sourced materials. For these reasons, this work enables the acquisition and use of syringe pumps in laboratories worldwide to be independent of funding and previous knowledge in programming and electronics.

 

Questions for the authors:

• Do you envision the possibility of repurposing 3D printers to build other devices used for research purposes? If so, do you plan to extend your work in that direction?

• If it becomes widely used, this type of approach to obtain devices is expected to have a disruptive impact in the manufacturing industry and in companies providing commercial solutions. What do you expect to be the industry’s reaction to this possibility in terms of the services they provide? In your opinion, what should that reaction be?

 

References

[1] W. Zeng, I. Jacobi, D.J. Beck, S. Li, H.A. Stone. Characterization of syringe-pump-driven induced pressure fluctuations in elastic microchannels, Lab. Chip. 15 (2015) 1110–1115. https://doi.org/10.1039/C4LC01347F.

[2] F. Zhao, D. Cambié, V. Hessel, M.G. Debije, T. Noël. Real-time reaction control for solar production of chemicals under fluctuating irradiance, Green Chem. 20 (2018) 2459–2464. https://doi.org/10.1039/C8GC00613J.

[3] N. Convery, N. Gadegaard. 30 years of microfluidics, Micro Nano Eng. 2 (2019) 76–91. https://doi.org/10.1016/j.mne.2019.01.003.

[4] J.M. Pearce, N.C. Anzalone, C.L. Heldt. Open-Source Wax RepRap 3-D Printer for Rapid Prototyping Paper-Based Microfluidics, J. Lab. Autom. 21 (2016) 510–516. https://doi.org/10.1177/2211068215624408.

[5] R. Khnouf, D. Karasneh, E. Abdulhay, A. Abdelhay, W. Sheng, Z.H. Fan. Microfluidics based device for the measurement of blood viscosity and its modeling based on shear rate, temperature, and heparin concentration, Biomed. Microdevices. 21 (2019) 80. https://doi.org/10.1007/s10544-019-0426-5.

[6] B. Wijnen, E.J. Hunt, G.C. Anzalone, J.M. Pearce. Open-Source Syringe Pump Library, PLOS ONE. 9 (2014) e107216. https://doi.org/10.1371/journal.pone.0107216.

[7] A.S. Booeshaghi, E. da V. Beltrame, D. Bannon, J. Gehring, L. Pachter. Principles of open source bioinstrumentation applied to the poseidon syringe pump system, Sci. Rep. 9 (2019) https://doi.org/10.1038/s41598-019-48815-9.

[8] P. Almada, P.M. Pereira, S. Culley, G. Caillol, F. Boroni-Rueda, C.L. Dix, G. Charras, B. Baum, R.F. Laine, C. Leterrier, R. Henriques. Automating multimodal microscopy with NanoJ-Fluidics, Nat. Commun. 10 (2019) 1223. https://doi.org/10.1038/s41467-019-09231-9.

[9] M. Del Rosario, H. S. Heil, A. Mendes, V. Saggiomo, R. Henriques. The field guide to 3D printing in microscopy. Preprints 2021, 2021050352. https://doi.org/10.20944/preprints202105.0352.v1.

Tags: 3d printing, diy, microfluidics, syringe pump

doi: https://doi.org/10.1242/prelights.29392

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