Driving macro-scale transformations in three-dimensional-printed biopolymers through controlled induction of molecular anisotropy at the nanoscale

Laia Mogas-Soldevila; Jorge Duro-Royo; Daniel Lizardo; George G Hollyer; Charles M Settens; Jordan M Cox; Johannes T B Overvelde; Elaine DiMasi; Katia Bertoldi; James C Weaver; Neri Oxman

doi:10.1098/rsfs.2023.0077

Driving macro-scale transformations in three-dimensional-printed biopolymers through controlled induction of molecular anisotropy at the nanoscale

Interface Focus. 2024 Jun 7;14(3):20230077. doi: 10.1098/rsfs.2023.0077. eCollection 2024 Jun.

Authors

Laia Mogas-Soldevila^{1

2}, Jorge Duro-Royo², Daniel Lizardo², George G Hollyer^{1

3}, Charles M Settens⁴, Jordan M Cox⁴, Johannes T B Overvelde⁵, Elaine DiMasi⁶, Katia Bertoldi⁷, James C Weaver^{4

8}, Neri Oxman^{2

9}

Affiliations

¹ DumoLab Research, University of Pennsylvania, Philadelphia, PA 19104, USA.
² Mediated Matter Group, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
³ Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
⁴ MIT.nano, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
⁵ Soft Robotic Matter, AMOLF Institute, Amsterdam 1098, The Netherlands.
⁶ Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁷ School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
⁸ Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02215, USA.
⁹ Oxman, New York, NY 10019, USA.

Abstract

Motivated by the need to harness the properties of renewable and biodegradable polymers for the design and manufacturing of multi-scale structures with complex geometries, we have employed our additive manufacturing platform that leverages molecular self-assembly for the production of metre-scale structures characterized by complex geometries and heterogeneous material composition. As a precursor material, we used chitosan, a chemically modified form of chitin, an abundant and sustainable structural polysaccharide. We demonstrate the ability to control concentration-dependent crystallization as well as the induction of the preferred orientation of the polymer chains through the combination of extrusion-based robotic fabrication and directional toolpathing. Anisotropy is demonstrated and assessed through high-resolution micro-X-ray diffraction in conjunction with finite element simulations. Using this approach, we can leverage controlled and user-defined small-scale propagation of residual stresses to induce large-scale folding of the resulting structures.

Keywords: additive manufacturing; biological materials; large-scale structures; molecular anisotropy; multiscale design; self-folding.