Microscale 3D Printed Pillars and Porous Polymeric Structures: Manufacturability and Micromechanics

Two‐photon polymerization (2PP) is an additive manufacturing technology capable of producing polymeric 3D nano‐ to mesoscale structures with design flexibility and sub‐micron resolution. This study investigates the influence of 2PP printing parameters on the morphology and mechanical properties of solid and porous microstructures fabricated from three commercial resins: IP‐Q, IP‐S, and IP‐polydimethylsiloxane (IP‐PDMS). To evaluate micromechanical behavior, micropillar compression tests are conducted using IP‐Q, which has not been extensively characterized. Porous structures retained 80–85% of the stiffness of solids for IP‐Q and IP‐S, and 50% for IP‐PDMS. Fourier transform infrared spectroscopy showed degrees of conversion of 38% for IP‐Q and 61% for IP‐S and IP‐PDMS. The optimal printing parameters for IP‐Q micropillars were a laser power of 50 mW, slicing distance (s) of 1.2 μm, and hatching distance (h) of 1 μm. These settings correspond to a peak laser intensity of 1.58 × 10 −11 W cm −2 , a focal spot diameter (dxy) of 3.17 μm, a Rayleigh length (zR) of 10.13 μm, and a voxel overlap (δ) of 0.6. These conditions yielded a Young's modulus of 3.7 GPa and yield strength of 75.21 MPa. Overall, the findings emphasize the challenges of parameter optimization when introducing porosity and comparing materials. The results provide a systematic framework for tailoring 2PP processing to guide biomedical microdevice design.