Multicomponent stress-sensing materials fabricated by 3D-printing-methodologies

Rupp, H. et. al., Macromolecular Rapid Communications, 2021

The preparation and characterization of mechanoresponsive, 3D-printed composites is reported using a dual-printing setup for both, liquid dispensing and fused-deposition-modeling. The here reported stress‐sensing materials are based on high- and low molecular weight mechanophores, including  poly(e-caprolactone)-, polyurethane-, and alkyl(C11)-based latent copper(I)bis(N‐heterocyclic carbenes), which can be activated by compression to trigger a fluorogenic, copper(I)-catalyzed azide/alkyne “click”-reaction (CuAAC) of  an azide-functionalized fluorescent dye inside a bulk polymeric material. The low-molecular weight mechanophores bearing the alkyl-C11 chains displayed the best printability, yielding a useful mechanochemical response after the 3D-printing process. © 2020 The Authors. Published by Wiley‐VCH GmbH