Nanoscale 3D Printing of Structural Colors and Multi-Spectral Filters for Light Control
Event details
| Date | 30.06.2025 |
| Hour | 12:00 › 13:00 |
| Speaker | Prof. Joel K.W. Yang, Department of Engineering Product Development, Singapore University of Technology and Design, Singapore (SG) |
| Location | Online |
| Category | Conferences - Seminars |
| Event Language | English |
PHOTONICS, MICRO- and BIOENGINEERING SEMINAR
Abstract:
3D printing is a cost-effective and effective means to rapidly prototype and test out designs. In our cleanroom, we use high-resolution 3D printers based on two-photon polymerization lithography (TPL) with light (780 nm wavelength femtosecond lasers) to quickly realize nanoscale structures that are designed to control light. Producing structures with TPL for optical applications is a relatively new endeavor in additive manufacturing [1], with capabilities to create freeform structures at dimensions matching the wavelength of light. We have demonstrated the printing of structural colors, generated from nanoscale features of dielectric materials. Examples include TPL printing of nanopillars, gratings, mesh-like, and wood-pile photonic crystal structures that appear colorful under white-light illumination. The ability to achieve a wide range of colors by simply tuning geometric properties opens fascinating opportunities to the nanoengineer or nanoscientist to design colors using material properties, and nanostructure geometry as input parameters. This physical approach differs from the chemical approach for synthesizing pigments and dyes, where colors arise due to optical absorption. We recently extended a “print and shrink” process to produce photonic crystals with bandgaps in the visible spectrum, e.g. see Fig. 1. We formulated resins that result in structures of both high and low index dielectrics, respectively titanium dioxide [2], and glass [3]. The 3D printed structures remarkably show excellent lattice uniformity with measured angle-dependent reflectance spectra that agree well with bandstructure calculations. Equipped with TPL as a nanoscale 3D printer, structural color geometries are conveniently integrated in a single print run with other user-defined optics. Doing so enables one to produce structured light from incoherent light sources, holographic color prints, and control of the light-field for 3D representation. We will discuss the use of structural colors combined with micro-optics for enhanced information content and optical security [4].
References
1. Hao Wang, et al. “Two-Photon Polymerization Lithography for Optics and Photonics: Fundamentals, Materials, Technologies, and Applications”, Adv. Funct. Mater. 2214211 (2023)
2. Wang Zhang, et al., “Printing of 3D photonic crystals in titania with complete bandgap across the visible spectrum”, Nature Nanotechnology volume 19, pages1813–1820 (2024)
3. Wang Zhang, et al.,“Nanoscale 3D printing of glass photonic crystals with near-unity reflectance in the visible spectrum”, Science Advances Vol 11, Issue 21(2025)
4. Hongtao Wang, et al. “Coloured vortex beams with incoherent white light illumination”, Nature Nanotechnology 18, 264–272 (2023)
Bio:
Joel Yang received his Master of Science (2005) and PhD (2009) degrees from the Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science. He is a Professor, Cleanroom Director and Associate Head of Department in Engineering Product Development at the Singapore University of Technology and Design (SUTD). He is recognized for pioneering work in plasmonic color printing, achieving record-level printing resolution at 100,000 dpi and credited for the widely-used “salty-developer” to improve the resolution of electron beam lithography. His research interests include Structural color printing, Nanoplasmonics, 2D and 3D printed nano optical design elements (NODE), and sub-10-nm resolution lithography. He is Fellow of Optica, NRF Investigator (class of 2020), and A*STAR Investigator (2010).
Zoom link for attending remotely: https://epfl.zoom.us/j/63256411470
Instructions for 1st-year Ph.D. students planning to attend this talk, who are under EDBB’s mandatory seminar attendance rule:
IN CASE you cannot attend in-person in the room, please make sure to
Abstract:
3D printing is a cost-effective and effective means to rapidly prototype and test out designs. In our cleanroom, we use high-resolution 3D printers based on two-photon polymerization lithography (TPL) with light (780 nm wavelength femtosecond lasers) to quickly realize nanoscale structures that are designed to control light. Producing structures with TPL for optical applications is a relatively new endeavor in additive manufacturing [1], with capabilities to create freeform structures at dimensions matching the wavelength of light. We have demonstrated the printing of structural colors, generated from nanoscale features of dielectric materials. Examples include TPL printing of nanopillars, gratings, mesh-like, and wood-pile photonic crystal structures that appear colorful under white-light illumination. The ability to achieve a wide range of colors by simply tuning geometric properties opens fascinating opportunities to the nanoengineer or nanoscientist to design colors using material properties, and nanostructure geometry as input parameters. This physical approach differs from the chemical approach for synthesizing pigments and dyes, where colors arise due to optical absorption. We recently extended a “print and shrink” process to produce photonic crystals with bandgaps in the visible spectrum, e.g. see Fig. 1. We formulated resins that result in structures of both high and low index dielectrics, respectively titanium dioxide [2], and glass [3]. The 3D printed structures remarkably show excellent lattice uniformity with measured angle-dependent reflectance spectra that agree well with bandstructure calculations. Equipped with TPL as a nanoscale 3D printer, structural color geometries are conveniently integrated in a single print run with other user-defined optics. Doing so enables one to produce structured light from incoherent light sources, holographic color prints, and control of the light-field for 3D representation. We will discuss the use of structural colors combined with micro-optics for enhanced information content and optical security [4].
References
1. Hao Wang, et al. “Two-Photon Polymerization Lithography for Optics and Photonics: Fundamentals, Materials, Technologies, and Applications”, Adv. Funct. Mater. 2214211 (2023)
2. Wang Zhang, et al., “Printing of 3D photonic crystals in titania with complete bandgap across the visible spectrum”, Nature Nanotechnology volume 19, pages1813–1820 (2024)
3. Wang Zhang, et al.,“Nanoscale 3D printing of glass photonic crystals with near-unity reflectance in the visible spectrum”, Science Advances Vol 11, Issue 21(2025)
4. Hongtao Wang, et al. “Coloured vortex beams with incoherent white light illumination”, Nature Nanotechnology 18, 264–272 (2023)
Bio:
Joel Yang received his Master of Science (2005) and PhD (2009) degrees from the Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science. He is a Professor, Cleanroom Director and Associate Head of Department in Engineering Product Development at the Singapore University of Technology and Design (SUTD). He is recognized for pioneering work in plasmonic color printing, achieving record-level printing resolution at 100,000 dpi and credited for the widely-used “salty-developer” to improve the resolution of electron beam lithography. His research interests include Structural color printing, Nanoplasmonics, 2D and 3D printed nano optical design elements (NODE), and sub-10-nm resolution lithography. He is Fellow of Optica, NRF Investigator (class of 2020), and A*STAR Investigator (2010).
Zoom link for attending remotely: https://epfl.zoom.us/j/63256411470
Instructions for 1st-year Ph.D. students planning to attend this talk, who are under EDBB’s mandatory seminar attendance rule:
IN CASE you cannot attend in-person in the room, please make sure to
- send D. Reinhard a note well ahead of time (ideally before seminar day), informing that you plan to attend the talk online, and, during seminar:
- be signed in on Zoom with a recognizable user name (not any alias making it difficult or impossible to identify you).
Practical information
- Informed public
- Free
Organizer
Contact
- Marie Rodriguez