AME hosted a guest lecture given by Dr. H. Jerry Qui on Monday, October 24, 2016. Dr. Qi presented his research regarding the design of active composites for 4D printing applications.
Recent advances in multimaterial 3D printing allow the precise placement of multiple materials at micrometer resolution with essentially no restrictions on the geometric complexity of the spatial arrangement. Complex 3D solids thus can be created with highly non-regular material distributions in an optimal fashion, enabling the fabrication of devices with unprecedented multifunctional performance. This also enables the emerging concept of 4D printing.
In his talk, Dr. Qi started with the concept of 4D printing, where he prints a composite in a relatively simple shape; after printing and some thermomechanical programming, the composite can change its shape as a function of time, the 4th dimension of the shape forming process. He further showed different designs to achieve the shape change, such as printed active composites and direct printing shape memory materials. To further enhance the functionality of the 4D printing, Dr. Qi explored the printing of conductive wires that can be used either for electric signal transfer or as heating elements. He investigated how different curing methods of the conductive ink can affect the electric properties as a function of strain.
Based on the knowledge learned, Dr. Qi can fabricate a stretchable electronic device in a sequential process. He demonstrated a stretchable LED circuit, a heating element for shape memory polymers, and a sensor to detect shape change. This method provides the opportunity to print complex 3D stretchable electronics, which will be integrated with 4D printing for topology transferring devices. Finally, Dr. Qi discussed the challenge and future directions for 4D printing.
Bio: Dr. H. Jerry Qi is Professor and the Woodruff Faculty Fellow in the George W. Woodruff School of Mechanical Engineering at Georgia Institute of Technology. He received his bachelor degrees and graduate degree from Tsinghua University and a ScD degree from Massachusetts Institute of Technology. After one year postdoc at MIT, he joined the University of Colorado Boulder as an assistant professor in 2004, and was promoted to associate professor with tenure in 2010. He joined Georgia Tech in 2014 and was promoted to a full professor in 2016.
Prof. Qi’s research is in the broad field of nonlinear mechanics of soft materials and focuses on developing a fundamental understanding of multi-field properties of soft active materials through experimentation and constitutive modeling then applying these understandings to application designs. He and his collaborators have been working on a range of soft active materials, including shape memory polymers, shape memory elastomeric composites, light activated polymers, covalent adaptable network polymers, for their interesting behaviors such as shape memory, light actuation, surface patterning, surface welding, healing, and reprocessing. Recently, he and his collaborators pioneered the 4D printing concept. Prof. Qi is a recipient of NSF CAREER award (2007). He is a member of Board of Directors for the Society of Engineering Science. In 2015, he was elected to an ASME Fellow.
