The technology is currently patent pending, and Otaigbe and Rahimi are working to optimize the process to make it commercially viable not just for the automotive industry, but all industries that use composites. They see big potential for these nanocomposites in construction and aerospace, two markets driven by a desire for lower costs and increased sustainability.

“The cost-effectiveness, lightweight, renewability and environmental sustainability of the nanocomposites of this study compared to that of traditional glass or carbon fiber reinforced (micro) composites may spur a better understanding of the current nanocomposites for a number of engineering applications where traditional carbon or glass fiber-reinforced polymer (micro) composites are not useable,” the researchers wrote in a paper about the project.

A New Approach to 4-D Printing

Project: Curved composites without molds

School: Concordia University

Location: Montreal

Principal Investigator: Suong Van Hoa, Ph.D.

The rise of 3-D printing has opened the door to a wave of new possibilities in manufacturing. However, while 3-D printing enables manufacturers to create a wide range of complex shapes, some researchers believe the process can be ever better. Many researchers have begun exploring 4-D printing, which allows regular 3-D printed structures with strategically aligned materials to self-fold like origami after being exposed to an activation mechanism like heat or moisture absorption.

composite-flower-4d-printing-concordia

By laying stacks of prepreg composite layers in an unsymmetrical laminate, Concordia University professor Suong Van Hoa, Ph.D., can control how they change shape. Photo Credit: Suong Van Hoa, Ph.D.

According to Suong Van Hoa, Ph.D., a professor in the Department of Mechanical, Industrial and Aerospace Engineering at Concordia University and director of the Concordia Center for Composites (CONCOM), typical 4-D printing uses flexible materials, such as rubber, which facilitate the process but don’t make parts particularly strong. CFRP, however, could provide that strength. In traditional manufacturing, creating a composite part with a curved shape would require the time-consuming process of building an expensive and complex mold, but thanks to Van Hoa’s latest research on additive manufacturing, that may no longer be necessary.

The key, he says, is anisotropy – the quality of exhibiting properties with different values when measured along axes in different directions. Van Hoa discovered that by using automated fiber placement (AFP) to lay down layers of a flat laminate containing fibers running in different directions, he can control how the laminate changes shape after it cures in an autoclave. The laminate can curve in a variety of ways depending on the manufacturer’s choice of material properties, lay-up sequence, fiber orientation, thickness and the strategic position of the laminate.