4D printing

4D printing (3D printing of a responsive material) is an emerging technology that utilizes additive manufacturing to fabricate shape-morphing structures.

Novel design concepts

I developed a technique to 4D print hydrogels composed of two types of voxels (3D pixels) that have different responses to an external stimulus and are small enough so that the discrete structure is smoothed by elasticity (i.e. like a black and white pixel map is smoothened to grayscale). These digital metamaterials can be encoded with an arbitrary geometry, providing great control over the resulting shape.

4D printing of digital metamaterials. Our technique allows one to simultaneously program lateral growth fields and spontaneous curvature.

Various printing materials

Additive manufacturing can be used with a variety of responsive materials. In my research, I have used thermoplastics, hydrogels, and wood.

Biomimetic structures 3D printed using ink composed of 100% wood materials. Each specimen was printed as a flat ribbon and morphed into a helical configuration upon drying. These structures and the associated shape transition mimic a seedpod.
Similar morphologies can be created from actuated PLA ribbons printed using a standard consumer FDM 3D printer.

E. Siéfert, I. Levin, and E. Sharon, Euclidean Frustrated Ribbons. Phys. Rev. X 2021 11
I. Levin, E. Siéfert, E. Sharon, and C. Maor, Hierarchy of Geometrical Frustration in Elastic Ribbons: shape-transitions and energy scaling obtained from a general asymptotic theory JMPS 156 104579 (2021)
D. Kam, I. Levin, Y. Kutner, O. Lanciano, E. Sharon, O. Shoseyov, and S. Magdassi Wood Warping Composite by 3D Printing Polymers 14 733 (2022)
I. Levin, E. Sachyani, R. Lieberman, N. Batat, E. Sharon, and S. Magdassi, 4D Printing of Programmable Digital Metamaterials arXiv:2406.12113 (2024)