Researchers create 3D printed objects that change shape

Researchers from the Georgia Institute of Technology lately created a technique in which 3D printers can be used for developing objects that are capable of expanding dramatically. The team believes that in the future, their invented object could be used in various fields from biomedical devices to space missions.

The shape-changing object makes use of a phenomenon called tensegrity – a structural system of floating rods in compression and cables in continuous tension. The struts of the object were then fabricated from shape memory polymers, which can unfold when heated.

A professor from the institute, Glaucio Paulino exclaimed, “Tensegrity structures are extremely lightweight while also being very strong. 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.”

The research reported in the journal Scientific Reports, informed that the struts being one of the main components of the tensegrity structure, thus, the team made use of 3D printers in order to create the struts. The researchers constructed the struts to be hollow with a narrow opening, which runs along the length of the tube. This in turn, allows the struts to be folded flat temporarily. Every strut contains an attachment point on each end to bond to a group of elastic cables. These points are too, created with 3D printers, per Tech Xplore.

The struts were heated to a temperature of 65 degrees Celsius that allowed the researchers to moderately flatten and fold them into a shape similar to W. When cooled, the structure retains the temporary form. The object can also be heated again to begin the transformation into tensegrity structures, this occurs when all cables are connected.

Another professor Jerry Qi expressed, “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.”

The struts of such object controlled the sequence and rate of expansion. The shape memory polymers also helped the researchers into fine-tuning how rapidly every strut expands by adjusting at which temperature the expansion happens. This further permits structures for designing with struts that can develop sequentially.

“For bigger and more complicated structures, if you don't control the sequence that these struts expand, it tangles and you have a mess. By controlling the temperature at which each strut expands, we can have a phased deployment and avoid this entanglement,” informed Paulino.

Science Daily informs that researchers believe that this newly developed structure can possibly be used for super light-weight structures that are required for space exploration and also for shape-changing soft robots. “These active tensegrity objects are very elegant in design and open up a range of possibilities for deployable 3-D structures,” described Paulino.