Volumetric Photopolymerization Confinement through Dual-Wavelength Photoinitiation and Photoinhibition

Area of Science:

• Photopolymerization
• 3D Printing Technologies
• Materials Science

Background:

• Conventional photolithography builds 3D objects layer-by-layer, limiting speed and requiring supports.
• Depth confinement is achieved by resin absorption at specific wavelengths, solidifying only thin layers.

Purpose of the Study:

• To explore butyl nitrite as a photoinhibitor for volumetric 3D printing.
• To enable in-depth polymerization control within a resin volume.
• To complement existing volumetric 3D printing techniques.

Main Methods:

• Investigated butyl nitrite's UV-activated photoinhibition of blue light polymerization.
• Utilized two perpendicular light patterns: blue for initiation, near-UV for inhibition.
• Demonstrated 3D photopolymerization patterning within bulk resin.

Main Results:

• Butyl nitrite effectively inhibited polymerization in a controlled manner.
• Independent control over polymerization initiation and inhibition was achieved.
• Volumetric patterning in bulk resin was successfully demonstrated.

Conclusions:

• Butyl nitrite enables precise depth control in photopolymerization.
• This approach facilitates volumetric 3D printing, potentially increasing fabrication rates.
• The method offers an alternative to layer-by-layer additive manufacturing.