By University of Colorado Boulder

Researchers at the University of Colorado Boulder (CU-Boulder) have successfully added a fourth dimension to their printing technology, opening up exciting possibilities for the creation and use of adaptive, composite materials in manufacturing, packaging and biomedical applications.

A team led by H. Jerry Qi, associate professor of mechanical engineering at CU-Boulder, and his collaborator Martin L. Dunn of the Singapore University of Technology and Design has developed and tested a method for 4D printing.  The researchers incorporated “shape memory” polymer fibers into the composite materials used in traditional 3D printing, which results in the production of an object fixed in one shape that can later be changed to take on a new shape.

4D Printing (Photo by Glenn Asakawa/University of Colorado Boulder)

“In this work, the initial configuration is created by 3D printing, and then the programmed action of the shape memory fibers creates time dependence of the configuration – the 4D aspect,” said Dunn, a former CU-Boulder mechanical engineering faculty member who has studied the mechanics and physics of composite materials for more two decades.

The 4D printing concept, which allows materials to “self-assemble” into 3D structures, was initially proposed by Massachusetts Institute of Technology faculty member Skylar Tibbits in April of this year. Tibbits and his team combined a strand of plastic with a layer made out of “smart” material that could self-assemble in water.

“We advanced this concept by creating composite materials that can morph into several different, complicated shapes based on a different physical mechanism,” said Dunn. “The secret of using shape memory polymer fibers to generate desired shape changes of the composite material is how the architecture of the fibers is designed, including their location, orientation and other factors.”

The CU-Boulder team’s findings were published last month in the journal Applied Physics Letters. The paper was co-authored by Qi “Kevin” Ge, who joined MIT as a postdoctoral research associate in September.

“The fascinating thing is that these shapes are defined during the design stage, which was not achievable a few years ago,” said Qi.

The CU-Boulder team demonstrated that the orientation and location of the fibers within the composite determines the degree of shape memory effects like folding, curling, stretching or twisting. The researchers also showed the ability to control those effects by heating or cooling the composite material.

Qi says 3D printing technology, which has existed for about three decades, has only recently advanced to the point that active fibers can be incorporated into the composites so their behavior can be predictably controlled when the object is subjected to thermal and mechanical forces.

The technology promises exciting new possibilities for a variety of applications. Qi said that a solar panel or similar product could be produced in a flat configuration onto which functional devices can be easily installed. It could then be changed to a compact shape for packing and shipping. After arriving at its destination, the product could be activated to form a different shape that optimizes its function.

As 3D printing technology matures with more printable materials and higher resolution at larger scales, the research should help provide a new approach to creating reversible or tunable 3D surfaces and solids in engineering like the composite shells of complex shapes used in automobiles, aircraft and antennas.

The research was funded by the Air Force Office of Scientific Research and the National Science Foundation.

For Further Contact:
Jerry Qi
720-470-9816
qih@colorado.edu

Courtney Staufer
CU Engineering Communications
303-492-7190
Courtney.staufer@colorado.edu

About
H. Jerry Qi, associate professor of mechanical engineering, holds simple models printed on a 3D printer using polymers that have “shape memory.” Qi and his collaborator Martin L. Dunn of the Singapore University of Technology and Design have developed and tested a method for 4D printing. The flat piece on the left can re-shape itself into the box with application of heat.

Quotes “The fascinating thing is that these shapes are defined during the design stage, which was not achievable a few years ago,” said H. Jerry Qi, associate professor of mechanical engineering at CU-Boulder.

About University of Colorado Boulder
As the flagship university of the state of Colorado, University of Colorado Boulder is a dynamic community of scholars and learners situated on one of the most spectacular college campuses in the country. As one of 34 U.S. public institutions belonging to the prestigious Association of American Universities (AAU) – and the only member in the Rocky Mountain region – we have a proud tradition of academic excellence, with five Nobel laureates and more than 50 members of prestigious academic academies.

CU-Boulder has blossomed in size and quality since we opened our doors in 1877 – attracting superb faculty, staff, and students and building strong programs in the sciences, engineering, business, law, arts, humanities, education, music, and many other disciplines.

Today, with our sights set on becoming the standard for the great comprehensive public research universities of the new century, we strive to serve the people of Colorado and to engage with the world through excellence in our teaching, research, creative work, and service.

• One of only 34 U.S. public research universities selected to be in the Association of American Universities (AAU), and the only one in the Rocky Mountain region
• Offering approximately 3,600 courses in 150 fields of study, in arts and sciences, business, education, engineering, environmental design, journalism, law, and music
• Seventy-eight degree programs at the bachelor’s level, 56 at the master’s level, and 53 at the doctoral level
• Seventy-eight research centers and institutes exploring the arts and sciences, business, education, engineering, environmental design, journalism, law, music and other disciplines
• Granted over 7,400 undergraduate and graduate degrees during the 2011–12 academic year
• The top provider of Peace Corps volunteers in 2010 and 2011 among all U.S. colleges and universities, with over 2,350 alumni Peace Corps volunteers coming from CU-Boulder since the program’s founding in 1961
• The source of more than one-third of all PhDs awarded annually in Colorado
• Home to five Nobel laureates (four in physics; one in chemistry) and four National Medal of Science winners
• Seventy-six new companies—from biotechnology, to aerospace, to renewable energy—based on CU faculty research discoveries since 1994, with over $1 billion in follow-on funding for those companies
• Faculty, staff, and students serving over 335,000 Coloradans each year through community and faculty outreach programs—with additional efforts across the nation and around the world
• A national leader in Science, Technology, Engineering, and Math (STEM) education research and innovation with a campus-wide STEM education research center launching in September 2012
• Research partnerships with federal labs across the Front Range of Colorado, in addition to dozens of research collaborations in countries all over the world
• Awarded more than $380 million in sponsored research funding in fiscal year 2012
• The only public university in the United States to design and build instruments that have flown on NASA missions to every planet in the solar system (as well as Pluto)
• Tied for #1 in atomic/molecular/optical physics with the Massachusetts Institute of Technology (MIT) every year since 2006 in the U.S. News & World Report graduate programs ranking
• The largest contributor to the University of Colorado’s $5.3 billion in overall economic impact on the state of Colorado in fiscal year 2011–12

The first public university to open its doors in Colorado and the flagship of the four-campus University of Colorado System, which also includes:

• University of Colorado Denver
• University of Colorado Anschutz Medical Campus
• University of Colorado Colorado Springs