K. Ding; M. Jain; S. Kalácska; A. Sharma; W.W. Koelmans; P. Schürch; G. Dehm; J. Michler; R. Ramachandramoorthy
Materials & Design 260 (2025) 115090
A honeycomb architecture exhibits a high strength-to-weight ratio and excellent energy absorption properties. At
the microscale, these architectures have great potential for packaging and protection applications. However,
fabrication and testing of micro-honeycomb architectures remain challenging, particularly under extreme
loading conditions. Here, we report the fabrication of microscale copper honeycomb architectures using an
additive manufacturing technique − localized electrodeposition in liquid. The printed micro-honeycombs were
mechanically tested under both quasi-static and high strain rate conditions using a piezo-based in situ setup inside
an SEM. The honeycombs exhibit excellent energy absorption properties under both quasi-static and high strain
rate conditions, with the specific energy absorption increasing by 65 % as the strain rate rises from 0.001 s−1 to
110 s−1. The copper honeycombs possess an ultrafine-grained microstructure that undergoes grain refinement
during both quasi-static and high strain rate testing. Our work demonstrates the feasibility and potential of
employing micro-honeycomb architectures as impact protection architectures for sensitive micro/nano-
electromechanical systems and microelectronics operating in extreme environments.