One of the unique challenges of 3D printing is that models that feature structures hanging in mid-air, like the spout of a teapot, also need temporary structures to support the soft extruded plastic until it hardens. This can result in a lot of wasted material, because those supports are just discarded afterwards. A new prototype 3D printer with a segmented floor that can rise to create temporary supports could radically reduce plastic waste.
A 3D printer that uses additive extrusion techniques (where a model is created by depositing layer after layer of material) usually features a stable, level printing bed on which the model can be slowly built up over time. The bed is made of a smooth material so the plastic 3D model can be easily separated when it’s complete, but that’s about as complex as it gets.
The flatter the surface of the bed, the better the 3D-printed results will be, but that also necessitates the creation of additional support structures that not only have to be carefully removed afterwards so as not to blemish the surface of the of the model, but also can’t be re-used for anything else. Plastic filament is cheap, but 3D printing is also starting to be used in the medical field for recreating tissue and organs, and the biomaterials used for that can be expensive—upwards of $1,000 for just a small bottle.
It’s a problem that researchers in this field have tried to solve through several methods, including 3D printers with complex five-axis printing arms, and even printing models inside a vat of viscous gel that’s thick enough to temporarily support a model during its creation. Researchers at the USC Viterbi School of Engineering in California have come up with an entirely different approach. Their prototype printer was in part inspired by pin art toys where 3D recreations of hands or faces can be created by a grid of metal pins that are free to move up and down at varying heights. Instead of pins, their 3D printer’s bed is made up of a grid of tiny squares that can independently move up and down to provide additional support for a complex 3D model as it’s being created. Their work on the printer was recently published in the Additive Manufacturing journal.
Earlier prototypes of the team’s upgraded 3D printer bed used a separate electric motor to raise each section, and at $10 each, plus the cost of control boards, it resulted in a 3D printer that costs well north of $10,000. With many 3D printers available now costing just a couple hundred bucks, that approach was prohibitively expensive, so the researchers redesigned the prototype so the entire system is now powered by just a single motor.
The 3D printer’s design doesn’t eliminate the need for support structures altogether, but its creators estimate the prototype can save around 35% of the materials normally needed to produce a complex model. But it’s not just a savings of materials and cost. Printing those extra support structures also adds time to a 3D print, and the researchers believe the rising bed could reduce print times by almost 40% on average. As 3D printers slowly move from churning out 3D trinkets to building entire houses, these improvements in efficiency and material use are going to be crucial for expanding the viability of 3D printing for large-scale manufacturing.