Engineering crack tortuosity in polymer-polymer composites through ordered pores

Luke F. Gockowski, Neil D. Dolinski, Roberto Chavez, Noy Cohen, Fabian Eisenreich, Stefan Hecht, Robert M. McMeeking, Craig J. Hawker, and Megan T. Valentine. Materials Horizons 7: 1854-1860 (2020).

Abstract

Multimaterial additive manufacturing is an enabling tool for exploring difficult to access structure–property relationships. In this work, a recently developed multimaterial printing approach, solution mask liquid lithography, is used to produce porous polymer–polymer composites inspired by tough, hierarchical structures found in nature. The results demonstrate that varying the size and packing of pores in the core structure leads to significant enhancement in crack deflection. Finite element analysis reveals that this enhancement is linked to geometry-dependent stress distribution.