Size effect in the compression of 3D polymerized micro-structures

Abstract

Micro/nanoscale additive manufacturing provides a powerful tool for advanced materials and structures, which contains complex and precise features. For instance, the feature resolution of two-photon polymerization (2PP) can reach 200 nm. At this scale, many new material properties will occur, and the influence of the size effect cannot be ignored. Therefore, it is necessary to assess changes in the material mechanical properties considering size effects. In this work, several micrometric polymeric specimens were printed via 2PP and then their mechanical properties were assessed using compression tests. Detailed printing, testing procedures as well as the effects of parameter settings are provided. The experimental results show that the changes in the microstructures' size have a direct effect on Young's modulus. In particular, large surface-volume ratio results in a higher Young's modulus. That is, the smaller the structure size, the higher the stiffness. The reported findings play a significant role in the development of fabrication strategies of polymeric microstructures where high stiffness accuracy is fundamental.