Abstract
Two-photon polymerization (TPP) enables the fabrication of intricate 3D microstructures with submicron precision, offering significant potential in biomedical applications like tissue engineering. In such applications, to print materials and structures with defined mechanics, it is crucial to understand how TPP printing parameters impact the material properties in a physiologically relevant liquid environment. Herein, an experimental approach utilizing microscale tensile testing (μTT) for the systematic measurement of TPP-fabricated microfibers submerged in liquid as a function of printing parameters is introduced. Using a diurethane dimethacrylate-based resin, the influence of printing parameters on microfiber geometry is first explored, demonstrating cross-sectional areas ranging from 1 to 36 μm2. Tensile testing reveals Young's moduli between 0.5 and 1.5 GPa and yield strengths from 10 to 60 MPa. The experimental data show an excellent fit with the Ogden hyperelastic polymer model, which enables a detailed analysis of how variations in writing speed, laser power, and printing path influence the mechanical properties of TPP microfibers. The μTT method is also showcased for evaluating multiple commercial resins and for performing cyclic loading experiments. Collectively, this study builds a foundation toward a standardized microscale tensile testing framework to characterize the mechanical properties of TPP printed structures.
| Original language | English |
|---|---|
| Article number | 2500228 |
| Journal | Small Science |
| Volume | 5 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2025 |
Funding
G.M. and T.G. contributed equally to this work. The authors acknowledge the funding support from the NSF (Awards 1826135, 1936065, 2143997), the NIH National Institutes of General Medical Sciences, R35GM150623, P20GM113126 (Nebraska Center for Integrated Biomolecular Communication), and P30GM127200 (Nebraska Center for Nanomedicine); the Nebraska Collaborative Initiative; and the Voelte-Keegan Bioengineering Support. Design and fabrication of the TPP structures were conducted at the Center for Nanophase Materials Sciences (CNMS) at ORNL, which is a DOE Office of Science User Facility. Manufacturing and characterization analysis were performed at the NanoEngineering Research Core Facility (NERCF). G.M. and J.R. are funded by the NSF Graduate Research Fellowship. G.M. and T.G. contributed equally to this work. The authors acknowledge the funding support from the NSF (Awards 1826135, 1936065, 2143997), the NIH National Institutes of General Medical Sciences, R35GM150623, P20GM113126 (Nebraska Center for Integrated Biomolecular Communication), and P30GM127200 (Nebraska Center for Nanomedicine); the Nebraska Collaborative Initiative; and the Voelte‐Keegan Bioengineering Support. Design and fabrication of the TPP structures were conducted at the Center for Nanophase Materials Sciences (CNMS) at ORNL, which is a DOE Office of Science User Facility. Manufacturing and characterization analysis were performed at the NanoEngineering Research Core Facility (NERCF). G.M. and J.R. are funded by the NSF Graduate Research Fellowship.
Keywords
- mechanical characterization
- tensile testing
- two-photon polymerization