Holographic tomographic volumetric additive manufacturing.

Area of Science:

• Additive Manufacturing
• Optical Engineering
• Bioprinting

Background:

• Photopolymerization-based 3D printing technologies are advancing rapidly.
• Tomographic Volumetric Additive Manufacturing (TVAM) enables rapid, support-free microfabrication.
• Previous TVAM utilized incoherent light patterning.

Purpose of the Study:

• To investigate the potential of holographic phase modulation for volumetric 3D printing.
• To improve light projection efficiency and precision in TVAM.
• To demonstrate fabrication of complex microstructures in various materials.

Main Methods:

• Implemented a light engine with holographic phase modulation for TVAM.
• Utilized computer-generated holograms with tiled holograms and point-spread-function shaping.
• Tested fabrication in acrylates and scattering, cell-laden hydrogels.

Main Results:

• Achieved over a 20-fold improvement in light projection efficiency compared to amplitude coding.
• Enabled diffraction-limited resolution and precise light control.
• Successfully fabricated millimetric 3D objects with 31 μm negative features in under a minute.
• Demonstrated printing in soft cell-laden hydrogels at high cell densities.

Conclusions:

• Holographic phase modulation offers a significant advancement for volumetric 3D printing.
• This technology enables high-efficiency, high-resolution, and rapid fabrication of microscale objects.
• The method is suitable for printing in both standard resins and complex biological materials.