MIT Researchers Release BEAVER, a Dual-Extruder 3D Printer for Biological Materials

Researchers at the Massachusetts Institute of Technology (MIT) have released everything you need to build an open source dual-extruder 3D printer for biological materials — a device they have dubbed the BEAVER.

"This work presents the design and fabrication of a novel, dual-extruder biotic 3D printer, tailored for precise deposition of natural biomaterials such as pectin, chitosan, and cellulose," researchers Jessa de Alva and Markus Buehler explain of the project. "Moving beyond the limitations of traditional thermoplastic extrusion which relies on non-renewable plastics and produces significant waste, this printer utilizes a syringe-based mechanical extruder to deposit viscous biotic material hydrogels."

"By providing a robust, customizable, and open-source platform," the pair continue, "this work aims to empower researchers, educators, and innovators to advance biomaterials research and expand the reach of sustainable additive manufacturing. The printer fosters a collaborative community and lays the groundwork for further exploration of biological designs and materials."

The BEAVER, a backronym for Biotic Extruder for Additive Volumetric Engineering and Research, is based on the same additive printing concepts as a traditional fused filament fabrication (FFF/FDM) printer — but where a normal 3D printer would heat solid plastic feed to a liquid, the team's creation is designed for materials of biological origin.

BEAVER is based largely on off-the-shelf components, pairing a Duet3D Duet 3 Main Board 6HC controller with a Raspberry Pi single-board computer. The system features, in its default configuration, two syringe-based print heads, allowing for multi-material printing — delivering, the team explains, "advanced biocomposites" with desirable features. Despite this, BEAVER is designed to be user-friendly — even for those without extensive 3D printing experience — and can make use of existing software, with a profile for PrusaSlicer and compatible slicers provided.

"To support the rapidly evolving field of biotic materials research," the researchers note, "BEAVER incorporates a forward-thinking, modular design. The system is adaptable to new biocomposites, tools, and techniques, featuring hardware designed for easy upgrades and software capable of managing diverse workflows and material properties. This ensures versatility for both current and future biotic fabrication applications."

A paper on BEAVER has been published in the journal Progress in Additive Manufacturing under open-access terms; hardware design files are available on GitHub under a Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) license — though the team states that, despite the block on derivative creations, "contributions and improvements from the community are welcome."