4D PRINTING AND STIMULI RESPONSIVE MATERIALS
Monday, May 7, 2018
1:30PM – 5:00PM
Stéphane Costeux, Dow Chemical
Session Abstract
Natural systems are well known for their ability to respond to environmental cues such as heat, light, and humidity in an autonomous fashion, allowing them to accomplish complex tasks such as morphological changes and actuation. Inspired by nature, stimuli-responsive materials have emerged as a new generation of smart materials with potential to influence myriad applications including smart packaging, biomaterials, and textiles, intelligent self-assembly, and actuators such as artificial muscles. This session will highlight leaders in the field of stimuli-responsive polymers, including those working on unique manufacturing methods such as 4D printing. Speakers will share their work on the ties between processing, properties, and performance of advanced polymeric materials such as shape memory polymers, liquid crystalline elastomers, and hydrogels with the ability to respond to temperature, light, or hydration.
1st Talk:
4D Printing Enabled by Active Polymers and Composites
Dr. Jerry Qi, Georgia Tech
Professor and Woodruff Faculty Fellow, School of Mechanical Engineering
2nd Talk:
Pixelated Polymers: Directing the Self-Assembly of Liquid Crystalline Elastomers
Dr. Timothy White, Air Force Research Laboratory
Technology Advisor, Materials and Manufacturing Directorate
3rd Talk:
4D Printing of Liquid Crystal Elastomers
Prof. Taylor Ware, University of Texas at Dallas
Assistant Professor, Bioengineering
4th Talk:
Intelligent Polyolefin: Communication Through External Stimuli
Dr. Marcia Pires, Braskem
Polymer Science Researcher
5th Talk:
Self-folding of Polymer Sheets Using Light
Prof. Michael Dickey, North Carolina State University
Alumni Distinguished Professor, Chemical & Biomolecular Engineering
6th Talk:
Environmentally-triggered snap-through in soft structures
Prof. Jordan Raney, University of Pennsylvania
Assistant Professor, Mechanical Engineering &Applied Mechanics
Panel Discussion:
4D printing and stimuli responsive materials: opportunities for plastics
All speakers
4D Printing Enabled by Active Polymers and Composites
ABSTRACT
Recent advances in digital manufacturing 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 this talk, we introduce the 4D printing enabled by active polymers and composites, where the shape of printed 3D object can change upon external stimuli as a function of time, the 4-th dimension of the shape forming process. We directly print a composite in its initial 3D configuration from a CAD file that specifies the geometry and location of active polymers, such as shape memory polymers, liquid crystal elastomers. After printing, the programmed action of the active polymers creates time dependence of the composite configuration change. This process has considerable design freedom to enable creation of composites with complex and controllable anisotropic thermomechanical behavior via the prescribed active polymer architecture, shape, size, orientation and even spatial variation of these parameters to assume complex three-dimensional configurations, including bent, coiled, and twisted strips, folded shapes. We also show how the active composites can be directly integrated with other printed functionalities to create devices; here we demonstrate this by creating a structure that can assemble itself, such as printed origami. Some of our recent progresses will be presented and the challenges for the future development of 4D printing will be discussed.
SPEAKER BIOGRAPHY
Dr. H. JERRY QI
Georgia Tech
Professor and Woodruff Faculty Fellow, School of Mechanical Engineering
Dr. H. Jerry Qi is a 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 (dual degree), graduate degrees from Tsinghua University (Beijing, China) and a ScD degree from Massachusetts Institute of Technology. After one year postdoc at MIT, he joined University of Colorado Boulder as an assistant professor in 2004. 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 fundamental understanding of multi-field properties of soft active materials through experimentation and theoretical modeling. 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 and are actively working of 3D/4D printing of active polymers and composites for multifunctionality. 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.
Pixelated Polymers: Directing the Self-Assembly of Liquid Crystalline Elastomers
ABSTRACT
Liquid crystalline materials are pervasive in modern society. It has been long-known that liquid crystalline materials in polymeric forms also exhibit exceptional characteristics in high performance applications such as transparent armor or bulletproof vests. A specific class of liquid crystalline polymeric materials referred to as liquid crystalline elastomers were predicted by de Gennes to have exceptional promise as artificial muscles, owing to the unique assimilation of anisotropy and elasticity. Subsequent experimental studies have confirmed the salient features of these materials, with respect to other forms of stimuli-responsive soft matter, are actuation cycles of up to 400% as well "soft elasticity" (stretch at minimal stress). In this presentation, I will summarize our recent efforts in developing materials chemistry amenable to directed self-assembly. Enabled by these chemistries and processing methods, we have prepared liquid crystal elastomers with distinctive actuation and mechanical properties. Notably, these materials are homogenous in composition (lacking material/material interfaces). Relevance of this work to implementations in aerospace and commercial applications will be discussed.
SPEAKER BIOGRAPHY
DR. TIMOTHY WHITE
Air Force Research Laboratory
Technology Advisor, Materials and Manufacturing Directorate
Dr. Timothy J. White is the Technology Advisor of the Photonic Materials Branch in the Materials and Manufacturing Directorate of the Air Force Research Laboratory. Tim received his Ph.D. in Chemical and Biochemical Engineering in 2006 from the University of Iowa. Subsequently he joined the Air Force Research Laboratory. Tim is active in all phases of research and development as leader of the "Responsive Photonic Materials" (RPM) group. The RPM group is an interdisciplinary team working basic, applied, and developmental research projects. Dr. White has been honored with the 2016 Materials Research Society "Outstanding Young Investigator" award, the 2013 SPIE Early Career Achievement award, the 2013 American Chemical Society PMSE Division Award for "Cooperative Research in Applied Polymer Science", and the 2012 Air Force Early Career Award. His research is generally focused on stimuli-responsive materials, with an emphasis on polymers and liquid crystals. Dr. White actively serves the broader materials research community in leadership activities with American Chemical Society (POLY), Materials Research Society, and SPIE.
4D Printing of Liquid Crystal Elastomers
ABSTRACT
Three-dimensional structures capable of reversible changes in shape, i.e. 4D printed structures, may enable new generations of soft robotics, implantable medical devices, and consumer products. Here, thermally-responsive liquid crystal elastomers (LCEs) are direct-write printed into 3D structures with controlled molecular order. Molecular order is locally programmed by the shear associated with extrusion, with the order following the print path used to build the 3D object. This order controls the stimulus-response. Locally, each aligned LCE filament undergoes a 40% reversible contraction along the print direction on heating. However, this combination of controlled geometry and stimulus-response in 3D enables the manufacture of objects capable of shape transformations that are atypical for this class of materials. For example, porous scaffolds can be designed to undergo reversible volumetric contraction on heating despite the isochoric nature of the stimulus-response in LCEs. Furthermore, we demonstrate that by printing shells with regions of both positive and negative Gaussian curvature, actuators that undergo rapid, repetitive snap-through transitions, can be realized. Finally, we will discuss expanding the use of this printing technique to a variety of liquid crystal inks, enabling fabrication of light and humidity responsive 3D structures.
SPEAKER BIOGRAPHY
PROFESSOR TAYLOR WARE
University of Texas at Dallas
Assistant Professor, Bioengineering
Dr. Taylor H. Ware is an Assistant Professor of Bioengineering at the University of Texas at Dallas. Prior to joining UT Dallas in August 2015, he graduated summa cum laude with his B.S. from the Georgia Institute of Technology (2009) and with his Ph.D. from the University of Texas at Dallas (2013) in Materials Science and Engineering. Taylor completed postdoctoral training at the Materials and Manufacturing Directorate at the Air Force Research Laboratory. His research interests include stimuli-responsive materials, flexible and stretchable electronics, biomaterials, and the interfacing of these technologies. Dr. Ware was a recipient of the National Science Foundation Graduate Research Fellowship (2011) and the Air Force Young Investigator Award (2017). He has also authored or co-authored of more than 40 scientific publications.
Intelligent Polyolefin: Communication Through External Stimuli
ABSTRACT
Braskem will highlight the trends in Smart Technologies and present some advances in Braskem´s research. The technology under development allows the polymer to change color by an external stimuli. The potential application in packaging will be presented as an opportunity to alert the consumer when the product is unfitted for consumption.
SPEAKER BIOGRAPHY
DR. MARCIA PIRES
Braskem
Polymer Science Researcher
Dr. Marcia Pires is a Polymer Science Researcher for Braskem, responsible for the research and development in Smart Packaging. She holds a Bachelor's degree in Chemistry and Industrial Chemistry from the Federal University of Rio Grande do Sul (UFRGS) and a Master's degree in Chemistry and a Doctorate degree in Materials Science of the same University. The doctor degree was focused on active packaging by the Material Science Program, being also held in the Packaging Science Department of the University of Clemson (USA). Dr Pires' experience includes Polymer characterization and polymer structure and properties correlation.
Self-folding of Polymer Sheets Using Light
ABSTRACT
This talk will discuss a simple approach to shape-program 2D sheets of polymer into 3D objects using 'self-folding'. Self-folding converts 2D templates into desired 3D shapes in a manner similar to origami, but does so in a hands-free manner. We achieve self-folding by locally heating pre-stressed polymer films. The heat causes the polymer to locally relax (i.e., shrink) and induces a folding response. The heat can be delivered using patterned light, patterned inks that absorb light, and patterned inks that absorb microwaves or other sources of energy. It is possible to control the sequence of folding by using inks that selectively absorb specific stimuli (e.g. certain wavelength of light). The ability to control sequence enables temporal control of folding and thus, the formation of more complex shapes. Self-folding takes advantage of the multitude of available 2D patterning techniques that can be employed to pattern these inks (e.g., lithography, inkjet printing, screen printing). Whereas folding occurs by localizing ink to 'hinge' regions, it is also possible to form shapes with Gaussian curvature (e.g. a sphere) by distributing the ink strategically over larger areas. Finite element modeling can predict these shapes. The self-folding strategy presented in this talk may provide a cost-effective 3D fabrication strategy for applications such as packaging, robotic actuators and sensors, biological devices, solar cells and reconfigurable devices.
SPEAKER BIOGRAPHY
DR. MICHAEL D. DICKEY
North Carolina State University
Alumni Distinguished Professor, Chemical & Biomolecular Engineering
Dr. Michael D. Dickey received a BS in Chemical Engineering from Georgia Institute of Technology (1999) and a PhD in Chemical Engineering from the University of Texas at Austin (2006) under the guidance of Professor Grant Willson. From 2006-2008 he was a post-doctoral fellow in the lab of Professor George Whitesides at Harvard University. In August 2008, he joined the Department of Chemical & Biomolecular Engineering at NC State University where he is currently an Alumni Distinguished Professor. He completed a sabbatical at Microsoft in 2016. Michael's research interests include patterning and actuating soft materials by studying and harnessing thin films, interfaces, and unconventional fabrication techniques.
Environmentally-triggered snap-through in soft structures
ABSTRACT
Dionaea muscipula, the Venus flytrap, is known for its ability to rapidly snap its leaves together to trap prey. However, in addition to this well-known behavior, the plant exhibits very complex sensing and control behavior (for example, it releases a captured object if it is too small or if it does not produce adequate stimulation of the hairs that emerge from the leaf). Nature teems with examples of such complex embodied logic, producing motion and morphological changes in response to specific cues (humidity, light, temperature, etc.) or sequences of cues. These behaviors emerge solely from compositional and structural features rather than from rigid sensors and actuators. Taking inspiration from such movements in plants, we 3D print nonlinear structural designs from materials that differentially swell in response to specific environmental cues (e.g., water or non-polar solvents). Rather than relying solely on diffusion-limited swelling, which is intrinsically slow, we fabricate nonlinear architectures near bifurcation points, allowing very small amounts of swelling to trigger rapid, large-amplitude shape changes at controlled intervals of time. This approach can be used to produce a rich variety of bioinspired autonomous systems without electronics or control systems. Using solely soft materials as functional elements, the proposed approach enables complex function to occur in response to multiple stimuli.
SPEAKER BIOGRAPHY
DR. JORDAN R. RANEY
Uinversity of Pennsylvania
Assistant Professor, Mechanical Engineering & Applied Mechanics
Dr. Jordan R. Raney is an assistant professor in the Department of Mechanical Engineering & Applied Mechanics at the University of Pennsylvania. He received a B.S. in Physics and a B.S. in Computer Science from the University of Minnesota. After this he joined the staff at MIT Lincoln Laboratory, prior to attending Caltech for graduate school, where he received a M.S. and Ph.D. in Materials Science. Before joining Penn, he was a postdoctoral fellow in the John A. Paulson School of Engineering & Applied Sciences and the Wyss Institute for Biologically Inspired Engineering at Harvard. His research focuses on the mechanics and fabrication of novel material architectures, including hierarchical, heterogeneous, fibrous, and soft systems.
