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Liviu Librescu Memorial Lecture: Robotic surfaces with tunable stiffness and reversible shape-morphing

Wednesday, April 14, 2021

2:30pm – 3:45pm 

Zoom Link:  Here

Chiara Daraio, the  G. Bradford Jones Professor

Mechanical Engineering and Applied Physics

Caltech

Abstract:

Robotic surfaces that can reshape and react to external stimuli offer opportunities to create soft, versatile machines that can multi-task, while interacting safely with their surroundings. Such systems are useful in applications that range from haptic interfaces, wearable exoskeletons and reconfigurable medical supports. Key properties of robotic surfaces include their ability to control their local stiffness, reprogram their target shape and have sufficient mechanical load bearing ability, to support weights and manipulate objects. In this talk, I will describe recent solutions developed in our group, to create structured fabrics that have tunable bending stiffness and robotic surfaces that allow for large, re-programmable, and pliable shape morphing into smooth 3D geometries. To develop these solutions, we design layered, architected materials, consisting of interlocking particles or networks of layered, polymeric ribbons. We employ different actuation methods, including vacuum pressure and Joule heating, to control the response of the surfaces.  We demonstrate the ability to fabricate fabrics that become >25 times stiffer than their relaxed configuration, when a small external pressure (~93 kPa) is applied. We also show that robotic surfaces consisting of layers of heat responsive liquid crystal elastomers (LCEs) can be reprogrammed to assume arbitrary shapes. 

Biography:

Chiara Daraio is the G. Bradford Jones Professor of Mechanical Engineering and Applied Physics at Caltech. She received her undergraduate degree in Mechanical Engineering from the Universita' Politecnica delle Marche, Italy (2001) and her M.S. (2003) and Ph.D. degrees (2006) in Materials Science and Engineering from the University of California, San Diego. She joined the Aeronautics and Applied Physics departments of the California Institute of Technology (Caltech) in fall of 2006 and was promoted to full professor in 2010. Between 2013-2016, she served as the chair of Mechanics and Materials at ETH Zürich. Chiara received numerous awards, among them, a Presidential Early Career Award from President Obama (PECASE) and an ONR Young Investigator Award. She was selected as a Sloan Research Fellow and she is a winner of the NSF CAREER award, of the Richard Von Mises Prize and of the Hetenyi Award from the Society for Experimental Mechanics. She was nominated by Popular Science magazine among the "Brilliant 10". She serves as a Board Editor for Science (AAAS) and as an Associate Editor for the journals Multifunctional Materials (IOP), Matter (Cell Press) and Frontiers in Materials (Frontiers).