Light-based 3D printing shows great potential in biomedical applications by providing high-resolution features. However, its high-resolution capability is severely hindered in 3D printing through biological tissues because of the optically turbid nature of the tissue. Here, we demonstrate a high-resolution additive manufacturing technique through scattering media using upconversion nanoparticles (UCNPs) and the wavefront shaping method. It uses near-infrared (NIR) light to photopolymerize through the scattering media via UCNPs, which act as a secondary source for UV light as well as a beacon for wavefront shaping. By exploiting the optical nonlinearity of the upconverted fluorescence and the memory effect correlations, high-resolution printing is experimentally demonstrated through strongly scattering layers and biological tissues even when the signal is not localized. This technique provides a proof of concept of 3D printing through turbid media with potential applications for in vivo 3D bioprinting.
3D printing technologies have significantly advanced the manufacturing of complex objects for use in various applications. Two-photon polymerization (TPP) has offered the highest resolution (around 100 nm lateral resolution) in 3D printing by introducing a non-linear absorption process. However, the extremely low probability of two-photon absorption requires pulsed lasers with high peak intensity, the cost of which strongly limits the broad dissemination of TPP. Here we propose 3D printing using upconversion nanoparticles (UCNPs) for tunable high-resolution printing of gelatin-based hydrogel while using continuous-wave lasers. Kinetic analysis of the process has been investigated and showed that the nonlinearity of UCNPs can be tuned by the excitation intensity. It offers the possibility of adjusting the voxel size together with the printing speed. This work provides new possibilities for high-resolution additive manufacturing at optimized fabrication speed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.