Summary of DIY SELF-ASSEMBLING 4D PRINTING
This article details an experiment by [Teaching Tech] to create 4D printed objects using a conventional 3D printer. The project focuses on a self-assembling hinge that changes shape when submerged in water. By utilizing a dissolvable locking mechanism made of PVA, the author successfully demonstrated how a structure can spring into its natural position once the lock dissolves, despite initial challenges with material deformation and multi-material printing complexities.
Parts used in the DIY Self-Assembling 4D Printing:
- TPU hinge
- TPU spring
- PLA structural beams
- PVA locks (dissolvable)
A 4D printed object is like a 3D printed object, but it changes shape or self-assembles when its environment changes. [Teaching Tech] has been reading about this technology and decided to try to replicate it using his conventional 3D printer.
His attempts to make a joint that changes when submerged in the water looked at several options: material that can absorb water, material that expands with temperature, and — the selected option — a dissolvable locking mechanism. Essentially, a hinge is held open by a water-soluble lock. When water dissolves the lock, the hinge can spring to its natural position.
Like most experiments, this one had a few false starts. But you always learn something each time. The final design had a TPU hinge and spring with PLA structural beams. The TPU required flat printing, so various pieces have to be rotatable so they can be placed in their final orientation after printing.
Usually, multi-material setups are for printing different colors of the same kind of plastic, it’s possible to use different plastics, but it can be tricky. As a compromise, [Teaching Tech] did one print using PLA and TPU, but printed the PVA locks in a separate pass and installed them on the print at the end. The first finished 4D print wasn’t entirely successful. The hot water slowly dissolved the PVA, but it also deformed the PLA. A redesign of the lock made a big difference.
We aren’t sure this is practical yet, but we are sure someone has a need for this technique and it could be made very practical with a little work. The last time we saw 4D printing, there were magnets involved. We think this is an exciting time where people aren’t just trying to get conventional printing to work well, but are pushing the envelope with new techniques like conical slicing, for example.
Source: DIY SELF-ASSEMBLING 4D PRINTING
- What is a 4D printed object?
A 4D printed object is like a 3D printed object but changes shape or self-assembles when its environment changes. - How does the hinge mechanism work in this project?
A hinge is held open by a water-soluble lock; when water dissolves the lock, the hinge springs to its natural position. - Which materials were selected for the final design?
The final design used a TPU hinge and spring with PLA structural beams. - Why was the PVA lock printed in a separate pass?
Multimaterial setups are tricky, so the author printed the PVA locks separately and installed them at the end. - What issue occurred with the first finished 4D print?
The hot water slowly dissolved the PVA but also deformed the PLA. - How did the author solve the PLA deformation problem?
A redesign of the lock made a big difference in solving the issue. - Can different plastics be used in multi-material setups?
Yes, it is possible to use different plastics, though it can be tricky compared to just printing different colors. - What alternative technique mentioned involves magnets?
The last time the author saw 4D printing, there were magnets involved.
