Launching stuff into space has always been a matter of great cost, ranging from around $9,000 to above $40,000 per pound. So, NASA has to look for a more innovative way to develop more compact payloads as weight and space are big factors when it comes to the cost. However, researchers from the Georgia Institute of Technology have used 3D printers to create tensegrity objects that can dramatically expand and change shape. Those 3D printed structures have the potential to be used in applications such as developing biomedical devices and in space missions where weight and size really matter.
The objects use tensegrity, otherwise known as tensional integrity, which is a structural principal of cables in continuous tension and floating rods in compression. It means the integrity of the object is comprised of the tension members’ balance. For this experiment, the research team has applied the principle of tensegrity with shape memory polymers, which can expand into certain shapes when exposed to heat.
“Tensegrity structures are extremely lightweight while also being very strong,” said Glaucio Paulino, a professor in Georgia Tech’s School of Civil and Environmental Engineering. “That’s the reason there’s a heavy amount of interest right now in researching the use of tensegrity structures for outer space exploration. The goal is to find a way to deploy a large object that initially takes up little space.”
Because of the objects ability to change shape over time, the method is often referred to as 4D printing. There are some projects that developed such objects. For instance, in collaboration with Georgia Tech, some researchers from Singapore have developed 4D printed objects, with another group exploring the durability of such structures. However, combining 4D printing with the principles of tensegrity is something new.
The researchers 3D printed the struts, which fulfill one of the primary components of the tensegrity structures; shape memory polymers. It enables the structure to unfold when heated up to 65 degree Celsius. Once cooled, the objects could retain the temporary shape. The researchers could reheat the objects with all those cables attached, which were also 3D printed using the Filaflex material.
If all goes well, the technology could be used to create lightweight objects like shape changing soft robots or devices for biomedical needs. Most importantly, it has the potential for space equipment where weight and size are important factors to be considered.
Explaining the potential for space, Jerry Qi, fellow researcher, and professor in the George W. Woodruff School of Mechanical Engineering at Georgia Tech said,
We believe that you could build something like an antenna that initially is compressed and takes up little space, but once it’s heated, say just from the heat of the sun, would fully expand.
And the best part is the International Space Station already has its own 3D printer, so there’s no need to launch those structures from earth.
The researcher was published in Scientific Reports under the title “Programmable Deployment of Tensegrity Structures by Stimulus-Responsive Polymers.”