Bulletin of the American Physical Society
APS March Meeting 2019
Volume 64, Number 2
Monday–Friday, March 4–8, 2019; Boston, Massachusetts
Session Y53: Towards Soft Active MetamaterialsInvited
|
Hide Abstracts |
Sponsoring Units: GSOFT Chair: Jorn Dunkel, Massachusetts Institute of Technology Room: BCEC 253C |
Friday, March 8, 2019 11:15AM - 11:51AM |
Y53.00001: Soft Active Metamaterials by Programing Ferromagnetic Domains Invited Speaker: Xuanhe Zhao Soft materials capable of transforming between three-dimensional (3D) shapes in response to stimuli such as light, heat, solvent, electric and magnetic fields have applications in diverse areas such as flexible electronics, soft robotics and biomedicine. In particular, magnetic fields offer a safe and effective manipulation method for biomedical applications, which typically require remote actuation in enclosed and confined spaces. With advances in magnetic field control, magnetically responsive soft materials have also evolved from embedding discrete magnets or incorporating magnetic particles into soft compounds to generating nonuniform magnetization profiles in polymeric sheets. Here we report 3D printing of programmed ferromagnetic domains in soft materials that enable fast transformations between complex 3D shapes via magnetic actuation. Our approach is based on direct ink writing of an elastomer composite containing ferromagnetic microparticles. By applying a magnetic field to the dispensing nozzle while printing, we reorient particles along the applied field to impart patterned magnetic polarity to printed filaments. This method allows us to program ferromagnetic domains in complex 3D-printed soft materials, enabling a set of previously inaccessible modes of transformation, such as remotely controlled auxetic behaviours of mechanical metamaterials with negative Poisson’s ratios. The actuation speed and power density of our printed soft materials with programmed ferromagnetic domains are orders of magnitude greater than existing 3D-printed active materials. |
Friday, March 8, 2019 11:51AM - 12:27PM |
Y53.00002: Bifurcations in mechanical structures: from smart folding to folding smarts Invited Speaker: Christian Santangelo Self-folding structures (also known as 4D printing) have emerged as a potential technique for the fabrication of complex structures in three dimensions, much as origami artists fold an intricate shape from flat sheets of paper. Recently, it has become clear self-folding origami exhibits a complex, bifurcated configuration space with exponentially many branches - making self-folding difficult. I will describe recent work extending this analysis to more complex origami having 2 or more degrees of freedom and explore, in detail, how to program a structure to fold robustly despite the proliferation of misfolding pathways. Finally, I will describe how to use the bifurcations and nonlinearities in origami and other mechanical structures to design “smart materials” - metamaterials that can perform logical operations. |
Friday, March 8, 2019 12:27PM - 1:03PM |
Y53.00003: Putting stubborn flocks to work Invited Speaker: Denis Bartolo Building on spontaneously flowing liquids assembled form colloidal rollers, I will show that (french) active colloids collectively protest and resist when one tries to waive their privilege to freely choose their direction of motion. I will show that the flows emerging from flocking transitions are intrinsically bistable and can proceed against external pressure gradients. I will theoretically explain this collective stubbornness showing that orientational elasticity and confinement conspire to protect the direction of spontaneous flows. Finally, I will show how to exploit the intrinsic bistability of confined polar liquids introducing a generic design principle for self-sustained microfludiic oscillators. |
Friday, March 8, 2019 1:03PM - 1:39PM |
Y53.00004: Manipulating the dynamics of active emulsions Invited Speaker: Chenyu Jin Precise control and manipulation are crucial to various applications of active matter. For example, in guidance applications as in active microsensors, microreactors with targeted release or microfluidic droplet logic, we need to know and control the rules by which such entities can be guided, follow external stimuli and control their stability. |
Friday, March 8, 2019 1:39PM - 2:15PM |
Y53.00005: Designing active topological networks Invited Speaker: Henrik Ronellenfitsch Mechanical and phononic metamaterials with exotic characteristics, including negative elastic moduli or |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700