EFRIFEST poster sm Workshop on Foldable, Buildable, & Responsive Materials from the micro scale to the building scale

August 22-23, 2014
Glandt Forum, Singh Center
University of Pennsylvania

Invited Speakers:

In-suk Choi (KIST)
Maria-Paz Gutierrez (UC Berkeley)
George W. Hart (Stony Brook)
Eleni Katifori (PENN & MPIDS)
Dan Luo (Cornell)
Spencer Magleby (Brigham Young)
Paul McEuen (Cornell)
Jenny Sabin (Cornell)
Skylar Tibbits (MIT)
Shu Yang (Penn)

Generously Supported by:

National Science Foundation
Simons Foundation
University of Pennsylvania Provost Interdisciplinary Seminar Fund
University of Pennsylvania Vice Provost for Research


Shu Yang Group, Kamien Group, University of Pennsylvania
Jenny Sabin, Sabin Design Lab, Cornell University


Day 1 – Friday Aug. 22  (Glandt Forum, Singh Center)
8:50 – 9:20 Breakfast
9:20 – 9:30 Welcome/Introduction – Randall Kamien (Penn)
Session 1:  Geometry, architecture and mechanics (Chair, Randall Kamien)
9:30 – 10:10 Talk 1 – Skylar Tibbits (MIT)
Self-Assembly & Programmable Materials
10:10 – 10:50 Talk 2 – Spencer P. Magleby (Brigham Young University)
Origami-Inspired Design of Mechanical Systems
10:50 – 11:20  Coffee
11:20 – 12:00 Talk 3 – In-suk Choi (Korea Institute of Science & Technology)
Engineering Shape and Structure of 2D Materials by Simple Fractal Cuts
12:00 – 1:30 Lunch
Session 2: Materials at the nano- and microscale (Chair: Eleni Katifori)
1:30 – 2:10 Talk 4 – Shu Yang (Penn)
From Adaptive Building Skins to Shape Changing and Super-Conformable Metamaterials
2:10 – 2:50 Talk 5Paul McEuen (Cornell)
Graphene Kirigami
2:50-3:10 Coffee
3:10- 3:50 Talk 6 – Dan Luo (Cornell)
From DNA with nano-clay: hydrogel-based, novel material building blocks
4:00 – 6:00 Poster session and Reception, DRL
Session 3: Public Lecture (David Rittenhouse Laboratory, DRL A4)
6:15-7:30 Talk 7 – George W. Hart (Stony Brook University)
Hands-On Constructions of 3D Structures
8:00 Dinner (on your own)
Day 2 – Saturday Aug. 23 (Glandt Forum, Singh Center)
9:00-9:30 Breakfast
Session 4: 3D printing and sewing in the macroscale and building scale (Chair: Annette Fierro)
9:30 – 10:10 Talk 8 – Eleni Katifori (Penn and Max Planck Institute DS)
Curved origami: folding of structures with non-zero Gaussian curvature
10:10 – 10:50 Talk 9 – Maria-Paz Gutierrez (UC Berkeley)
Building Cells and not Blocks: Multifunctional Matter & Multiscale Fabrication
10:50 – 11:20 Coffee
11:20 – 12:00 Talk 10 – Jenny Sabin (Cornell)
Elasticity and Networks
12:00 – 1:30 Lunch


Self-Assembly & Programmable Materials
Skylar Tibbits, Department of Architecture, MIT

There is a disciplinary convergence upon us, one that spans from the nano-scale to the human-scale. We are now able to program nearly every material from bits to DNA, proteins, proto-cells, smart materials, even products and infrastructure. There is a growing demand to translate these capabilities into solutions for large-scale applications rather than purely small-scale technologies At the Self-Assembly Lab, we aim towards the built-environment, from manufacturing, construction, infrastructure and products to develop more adaptive and highly resilient systems.  We have demonstrated that self-assembly is scale-independent and have produced prototypes transforming from 1D, 2D to 3D and even 4D Printing aimed at inventing a future of programmable built environments. 

Origami-Inspired Design of Mechanical Systems
Spencer Magleby, Mechanical Engineering, Brigham Young University

Origami artists have spent millions of hours developing complex origami models under extreme constraints of using only one material (paper) and one fabrication process (folding).  This has resulted in a rich collection of shapes and imbedded kinematics that can be made accessible to engineers through recent developments in modeling, and expanded through mathematical understanding.  Compliant Mechanisms are motion systems that gain some or all of their motion from the deflection of flexible members.  This presentation reports on results of our work to unite principles of origami, compliant mechanisms and mechanics to enable and promote the creation of novel and innovative mechanical systems.

The presentation focuses on results of two key objectives of the research: (1) overcome obstacles limiting origami principles from being widely applied to non-paper materials and (2) create design methods that unite origami and compliant mechanism principles.  Applications of these results to new technologies and systems are presented with emphasis on areas including rigid foldability, bi-stability, non-paper materials, thick materials, arrays, integration with actuation and tailorable sheet morphing.

Engineering Shape and Structure of 2D Materials by Simple Fractal Cuts
In-Suk Choi, Korea Institute of Science and Technology

In this presentation, we discuss the ability of a 2D material to differentiate into forms with a wide range of desired shapes and patterns by introducing fractal cuts: a set of simple cuts that can be arranged in a multi-level hierarchy and/or with different motifs. By putting simple cuts in the right geometry, we demonstrate that we can engineer a variety of material morphologies without changing the structural properties of the initial material. We can draw an analogy between our new concept and the well-known cell biology term pluripotency which refers to the potential of a stem cell to differentiate into very many cell types. In our case, the base 2D solid material acts as the pluripotent stem cell in the sense that it can differentiate into a wide range of structures. Upon stretching our 2D pluripotent materials, a completely new set of structures can be produced compared with the original material depending on encoded fractal cuts. The concept was experimentally realized and applied to the stretchable electrode by utilizing highly flexible and expandable nature (> ~800% in area) without deforming the basic units during stretching. Since the approach is general, this universal design strategy of pluripotent materials can be applied to tune material structures for various applications.

From Adaptive Building Skins to Shape Changing and Super-Conformable Metamaterials
Shu Yang, Department of Materials Science & Engineering, University of Pennsylvania

Reconfigurable soft metamaterials that can bend, fold, or transform the shape in response to external stimuli have attracted significant interests in design of actuators, sensors, and smart materials and devices. First, we fabricate tilted polymeric pillar arrays and colloidal particle dispersions, which can change the optical properties from opaqueness to colorful display to transparent windows in respond to environmental cues, such as proximity, touching, heat and light. By coupling the materials-environment response at the nano- and microscales with CMOS technology, we demonstrate adaptive building skins with autonomous tracking/imaging/sensing ability and feedback control systems. Further, we create polymeric sheets with periodic hole arrays based on kirigami (cutting + folding) principle, leading to dramatic shape changing (thus, different properties) even when modest stresses are applied. By introducing fractal cuts of various motifs, we demonstrate super-flexible and conformable metamaterials, which can be integrated with conventional rigid devices (e.g., LEDs, circuits, and RF antenna) without sacrificing device performance during collapsing or stretching.

Graphene Kirigami
Paul L. McEuen, Department of Physics and the Kavli Institute at Cornell for Nanoscale Science, Cornell University  

For centuries, practitioners of the paper arts of origami (“ori” = fold) and kirigami (“kiri” = cut) have created beautiful and complex structures from a simple sheet of paper. Scientists and engineers are beginning to apply these techniques to other materials, and this approach is proving its extraordinary potential many across disciplines. Here we show that graphene, an atomically thin sheet of carbon atoms, is a perfect starting material for micro- and nanoscale kirigami. We first demonstrate that we can, with the right tools, pick up monolayer graphene and manipulate it like a sheet of paper. This technique allows us to characterize the out-of-plane bending stiffness of graphene for the first time, and we find a bending stiffness thousands of times higher than simple expectations. We show that this surprising result can be explained by theoretical predictions of thermally-induced fluctuations in the membrane. We then apply ideas from kirigami to pattern the graphene into a variety of shapes and explore their properties. These include stretchable electrodes, springs, and robust hinges. This simple but powerful approach promises resilient, customizable, and functional moving parts at the micro- and nanoscale.

From DNA with nano-clay: hydrogel-based, novel material building blocks
Minglin Ma and Dan Luo, Department of Biological and Environmental Engineering, Cornell University

DNA, the molecule of life, provides programmable and versatile routes for building up novel materials that can be used for both genetic and generic purposes.  Recently we have achieved a variety of DNA-based hydrogels with unusual properties including a protein-producing hydrogel and a mechanical meta- hydrogel. Clay, perhaps the “molecule” of dirt, provides extremely inexpensive (“dirt cheap”) and robust routes for building up materials that can be used at macro- and building-scale. Recently we have demonstrated that nanoclay formed hydrogels in ocean water spontaneously and instantaneously and that nanoclay interacted and protected DNA. We hypothesize that DNA-based hybrid materials such as DNA-clays offer unique opportunities for origami materials. In this talk, I will present our first attempts and progresses towards fabricating DNA-clay-hybrid-based, transformable and responsive, novel building blocks with extremely large amounts. It is envisioned that these micro-scale hybrid building blocks can be designed, patterned and organized into macro-scale materials with desirable folding properties and functions.

Hands-on Constructions of Large-Scale 3D Structures
George W. Hart, Stony Brook University

Many fascinating structures can be built as large-scale physical models, illustrating patterns from crystals, nanostructures, and other sources.  Hart specializes in creating interesting structures using many techniques and materials, including 3D printing, laser-cutting, large sheets of cardboard, or household objects such as CDs or shish kabob skewers.  Often he leads large groups of people in assembling giant models that illustrate interesting structural arrangements.  This talk will incorporate many images and short videos to survey a variety of large-scale projects and will point to instructions for making your own versions of these fun 3D constructions.   

Bio: George Hart is a sculptor and applied mathematician who demonstrates how mathematical structures are cool and creative in ways you might not have expected. Whether he is slicing a bagel into two linked halves or leading hundreds of participants in an intricate geometric sculpture barn raising, he always finds original ways to share the beauty of mathematical thinking.  An interdepartmental research professor at Stony Brook University, he holds a B.S. in Mathematics and a Ph.D. in Electrical Engineering and Computer Science from MIT.  Hart is an organizer of the annual Bridges Conference on mathematics and art and the editor for sculpture for the Journal of Mathematics and the Arts. His research explores innovative ways to use computer technology in the design and fabrication of his artwork, which has been exhibited widely around the world. Hart co-founded the Museum of Mathematics in New York City and developed its initial set of hands-on exhibits.  He also makes videos that show the fun and creative sides of mathematics.  See http://georgehart.com for examples of his work.

Curved origami: folding of structures with non-zero Gaussian curvature
Eleni Katifori, Department of Physics and Astronomy, University of Pennsylvania and Max Planck Institute for Dynamics and Self-Organization

Thin curved shells that undergo large deformations are very common in biology, manifesting in structures such as seed pods or pollen grains. Pollen grains can reversibly fold and unfold to accommodate volume loss due to dehydration. The non-uniformity of the thin pollen shell, where usually there are areas (termed apertures) with reduced or absent pollen wall, guides the deformation pathway and determines the folded shape. Inspired by this folding process and by a large class of mono-aperturate pollen, we investigate what is the behavior of a thin spherical shell with a single opening of $n$-fold axial symmetry when compressed. We address this question via a series of experiments (3D scanning of compressed ping-pong balls), theory (geometry of constant Gaussian curvature surfaces) and simulations (tethered mesh algorithms). We analytically derive a two-parameter family of approximately isometric, constant positive Gaussian curvature shapes that is in excellent agreement with our experimental results of deformed shells and the tethered membrane simulations. We examine the properties of the folded shells and deduce the conditions that facilitate isometric folding. Finally, we discuss possibilities and limitations in generalising our methodology to describe large scale deformations of more general, doubly curved shapes.

Building Cells and not Blocks: Multifunctional Matter & Multiscale Fabrication
Maria-Paz Gutierrez (UC Berkeley)

The primary concentration of thermal gains (heat and light) and humidity transfer in buildings occurs through external enclosures. If the energy and material flows are synergistically optimized through a material programmed with self-regulation, the enclosure becomes, as in nature, a multifunctional skin. By operating through zero energy input or maintenance and no emissions these multifunctional skins can radically transform resource efficiency. Self-active matter is the new passive architecture. Yet, to accomplish such enclosures for architectural applications carries multiple obstacles ranging from multi-criteria optimization models to multiscale fabrication processes. Yet, the development of materials with programmed multifunctional capabilities for architecture is largely limited by the difficulty of calibrating responses for multiple climate inputs and the lack of integration of nano and microscale fabrication technologies required for the production of such multi-responsive materials. This presentation will discuss new frontiers in hybrid 3D printing through the research of BIOMS (UC Berkeley) led by P. Gutierrez. The presentation will focus on the critical gaps and research opportunities in multiscale fabrication of multifunctional materials enabled through the convergence of science, architecture and engineering in multiscale design.

Elasticity and Networks
Jenny Sabin, Department of Architecture, Cornell University

The ability to forgo disciplinary boundaries allows for unique views of similar issues, even at radically different physical & temporal scales. Sabin’s collaborative research, teaching and design practice focus on the contextual, material and formal intersections between architecture, science and technology. The scope of Sabin’s work probes the visualization of complex spatial data sets alongside issues of craft, fabrication and production in a diverse array of material systems. This work exhibits a deep organicity of interrelated parts, material components and building ecology. Generative design techniques emerge with references to natural systems, not as mimicry but as trans-disciplinary translation of flexibility, adaptation, growth and complexity into realms of architectural manifestation. This talk will look at intersections between architecture, computational models, textile structures, materials science and biology through multiple modes of working and collaborating. The material world that this type of research interrogates reveals examples of nonlinear fabrication and self-assembly at the surface, and at a deeper structural level. In parallel, this work offers up novel possibilities that question and redefine architecture within the greater scope of generative design, fabrication and building ecology.