MAE Webinar: Digital 4D Printing for Engineered Living Materials

Abstract: Engineered living materials refer to artificial materials systems that have attributes of living systems, including the ability to sense the presence of external stimuli and adapt to the changing environment. Such materials systems offer tremendous potential for autonomous and intelligent engineering systems when precisely manufactured in specific architectures with programmed responses. The emerging pathway to create dynamic and adaptive mechanical systems involves additive manufacturing (often called 3D printing) of responsive materials. This approach has been recently termed “4D printing,” with the fourth dimension being time.

In this seminar, 4D printing of responsive materials using projection micro-stereolithography (PµSL) will be presented. PµSL is a micro 3D printing technique that turns light into a complex 3D structure by utilizing the state-of-the-art digital display. Combining rapid, versatile and scalable micro 3D printing technique with smart materials, design principles and mechanics inspired by exquisite motions and morphologies in nature are physically realized. Micro-structures that can transform, move and even jump are demonstrated by programming of dynamic response of various responsive hydrogels. In addition, unprecedented access to micro- and nano-scale afforded by precision micro 3D printing allows for implementation of mechanics-driven design principles in micro-architectures, leading to mechanical properties far superior to those found in nature, such as ultra-low density and high stiffness. Furthermore, geometrically reconfigurable, functionally deployable and mechanically tunable lightweight material is created through 4D printing with a shape memory polymer.

Bio: Howon Lee is an assistant professor in the Department of Mechanical and Aerospace Engineering at Rutgers University – New Brunswick. He received his bachelor's and master's degrees from Seoul National University in 2004 and 2006, respectively, and a doctorate from the University of Illinois at Urbana-Champaign in 2011, all in mechanical engineering. He then held a Battelle/MIT postdoctoral fellow position at MIT before he joined Rutgers in 2014. His research group at Rutgers is currently involved in a wide spectrum of research including advanced manufacturing, mechanics of smart materials, mechanical metamaterials and biomedical engineering.