3D Printing of Natural Composites

Date and Time: 
Thursday, January 30, 2020 - 11:30am
Speaker: 
Yijie Steven Jiang PhD
Affiliation: 
University Of North Texas, Assistant Professor
Abstract: 
There is growing research interest in developing engineering materials that are renewable and sustainable from natural resources. Many ancient Chinese structures, such as the Great Wall, used a unique mortar that derives from sticky rice. Inspired by the long-term stability of the amylopectin-based mortars in ancient structures, we develop 3D printable sticky rice (SR)-based biocomposites. Unlike other types of rice, sticky rice is rich in amylopectin, a biopolymer with large molecular weight and branch chains. Thermal treatment causes gelatinization of amylopectin, namely molecular branches open to form a large network of gel balls. This causes a merger of the granules and improved interaction between the matrix and fillers. To enhance the mechanical properties, cotton fibers are included. Both the fibers and matrix constitute a 3D printable fiber composite consisting entirely of natural, inexpensive, and scalable components. The processing steps make no use of any non-natural materials or hazardous chemicals. Investigation of process-structure-property relationships is performed to understand the effect of processing parameters on the mechanical properties. Scalability by printing low-density cellular materials is demonstrated. Compared with thermoplastic composites, the 3D printed SR composites are more resilient when subjected to flame, heat, or ultraviolet light.
Biography: 
Dr. Yijie Jiang is an assistant professor in the Department of Mechanical and Energy Engineering at University of North Texas since Fall 2019. Dr. Jiang’s research focuses on combining design, fabrication and characterization at multiscale to achieve extraordinary mechanical properties and novel functionality. As the principal investigator of Multiscale Fabrication and Characterization (MFC) lab, he interests in advanced manufacturing of architected composites, incorporating micro/nano-materials in 3D printing, developing natural materials and sustainable manufacturing, and mechanical characterization at multiscale. Dr. Jiang received his PhD and Master degree in Mechanical Engineering and Applied Mechanics from University of Pennsylvania in 2017 and 2013, respectively. He received his Bachelor degree in Theoretical and Applied Mechanics from Fudan University, China.