Design and characterization of a multilayered multifield-actuated polymer unimorph

Rui Leng, Oliver Uitz, Zoubeida Ounaies, Carolyn Seepersad

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In this study, we design, fabricate and characterize a novel unimorph-like structure in which a shape memory polymer (SMP) is actuated using a magneto-active elastomer (MAE), resulting in contactless and large deformation shape change. The constituent materials are: A two-part elastomer, iron oxide microparticles, and a rapid cure epoxy. Combining the elastomer with the iron oxide particles results in an MAE actuator, such that application of an external magnetic field induces dipoles in the iron oxide particles, resulting in the actuation of the MAE. The shape memory epoxy polymers are deformed at an elevated temperature and cooled to lock-in the temporary programmed shape. Subsequent exposure to elevated temperature can then recover a permanent geometry. In a first step, the layered unimorph structure is fabricated using casting techniques in which the SMP serves as the 'passive' substrate, and the MAE is cast on top of this substrate or joined post-processing using adhesives. To demonstrate shape change, the unimorph is heated beyond the transition temperature of the epoxy, and a magnetic field is applied to deform the structure. Upon cooling, the shape change is locked into place. This configuration serves as proofof-concept that the proposed magnetically-responsive polymers are capable of eliciting the shape change of an SMP through bending in response to an external magnetic stimulus. After demonstrating feasibility, the next step is to use additive manufacturing (AM) to produce both the SMP and MAE by developing and tuning MAE and SMP resin formulations for printability. Printability is assessed by characterizing the viscosities, effective yield stress, gelation times, and extent of cure of the material formulations. The bending response of the layered structure is characterized as a function of magnetic field, material composition, geometric parameters, and AM process settings. The outcome of this research is to enable AM of smart materials and devices that can monitor and adapt to their environment. The medical device industry in particular stands to benefit from customizable devices that adapt their shape for particular patients, diseases, and/or stage of healing.

Original languageEnglish (US)
Title of host publicationProceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791885499
DOIs
StatePublished - 2021
EventASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021 - Virtual, Online
Duration: Sep 14 2021Sep 15 2021

Publication series

NameProceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021

Conference

ConferenceASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021
CityVirtual, Online
Period9/14/219/15/21

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Mechanics of Materials
  • Artificial Intelligence

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