title: Multimaterial 4D Printing with Tailorable Shape Memory Polymers.
abstract: We present a new 4D printing approach that can create high resolution (up to a few microns), multimaterial shape memory polymer (SMP) architectures. The approach is based on high resolution projection microstereolithography (PμSL) and uses a family of photo-curable methacrylate based copolymer networks. We designed the constituents and compositions to exhibit desired thermomechanical behavior (including rubbery modulus, glass transition temperature and failure strain which is more than 300% and larger than any existing printable materials) to enable controlled shape memory behavior. We used a high resolution, high contrast digital micro display to ensure high resolution of photo-curing methacrylate based SMPs that requires higher exposure energy than more common acrylate based polymers. An automated material exchange process enables the manufacture of 3D composite architectures from multiple photo-curable SMPs. In order to understand the behavior of the 3D composite microarchitectures, we carry out high fidelity computational simulations of their complex nonlinear, time-dependent behavior and study important design considerations including local deformation, shape fixity and free recovery rate. Simulations are in good agreement with experiments for a series of single and multimaterial components and can be used to facilitate the design of SMP 3D structures.
authors: Digital Manufacturing and Design Center, Singapore University of Technology and Design, Singapore.|Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors: Qi
authors: Q
authors: Ge
authors: Digital Manufacturing and Design Center, Singapore University of Technology and Design, Singapore.
authors: Amir Hosein
authors: AH
authors: Sakhaei
authors: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors: Howon
authors: H
authors: Lee
authors: The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
authors: Conner K
authors: CK
authors: Dunn
authors: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors: Nicholas X
authors: NX
authors: Fang
authors: Digital Manufacturing and Design Center, Singapore University of Technology and Design, Singapore.
authors: Martin L
authors: ML
authors: Dunn