4-D printing yields ‘smart’ structures that can change shape on demand

Video: College of Engineering

A team of Texas A&M University researchers is using 4-D printing to create nickel-titanium structures can change their physical shape or properties on demand when a stimulus, such as a temperature change or magnetic field, is applied.

“Our goals are to achieve the ability to manufacture ‘smart’ monolithic metallic structures that will respond to stimuli over time and have a different location-dependent stimulus response within the same part,” Alaa Elwany, a team member and an assistant professor in the Department of Industrial and Systems Engineering, College of Engineering, said. “In our case, this is retaining their original shape upon being subjected to a temperature stimulus.”

The materials have a “remembered shape,” Ji Ma, an assistant research scientist with the Texas A&M Engineering Experiment Station, said. “If you bend it out of shape, the material will go back to its original shape after being heated.”

While other work has been conducted in this area, the materials previously tested returned to the remembered shape after heating to one specific temperature. The team’s work now makes it possible for different parts of the same piece to return at different temperatures. This provides the ability to create devices that can assume multiple different shapes at different temperatures.

The team has also expanded on previous work by going beyond simple material shapes, such as wires, to more complex shapes due to the properties created from the various processing parameters used in the 3-D printing process. As a result of their research, this is the first time complex materials with multiple programmable shapes have been possible, the team said

The research group also includes Ibrahim Karaman, department head and Chevron Professor I, and Raymundo Arróyave, associate professor, both from the Department of Materials Science and Engineering, which is jointly operated by the College of Engineering and the College of Science.

The team’s research was published in Scientific Reports.

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