SUTD 3D Prints ColorRouter Structures for Low-Light Imaging
Four nanopillars made from a low-index polymer route RGB light toward sensor regions instead of absorbing unwanted wavelengths.
Nanjixiong reported on October 23, 2026 that a research team led by the Singapore University of Technology and Design (SUTD) had fabricated polymer “ColorRouter” structures using two-photon polymerization (2PP). The peer-reviewed paper was published in Nature Communications on August 27. Unlike a Bayer array that absorbs unwanted wavelengths, the structure uses scattering and interference to direct red, green and blue light toward their corresponding sensor regions.
Each unit cell contains four cylindrical nanopillars with different dimensions, printed in IP-L resin with a refractive index of about 1.5. The smallest features are approximately 150 nm. The team printed roughly 250,000 cells over an area of about 1 × 1 mm², reporting routing efficiency close to 90% in simulation and around 70% transmission/routing efficiency in the fabricated device. In a monochrome-sensor experiment, the routed image showed good color reproduction at roughly one-third the exposure time of the filtered reference.
Those results come from the paper’s laboratory setup, not a commercial camera. At this stage, 2PP is a design-validation method. Manufacturing deployment would require materials and processes compatible with replication methods such as nanoimprinting, direct integration on image sensors, and improvements to color crosstalk and angle-of-incidence tolerance. The researchers used a relatively simple 2.5D geometry without complex overhangs or enclosed cavities to keep future replication feasible.
Key facts
- Paper published August 27, 2026 in Nature Communications
- Fabrication: two-photon polymerization (2PP)
- Material: low-index IP-L resin, refractive index about 1.5
- Structure: four cylindrical nanopillars per cell; minimum feature about 150 nm
- Prototype scale: about 250,000 cells across roughly 1 × 1 mm²
- Fabricated-device transmission/routing efficiency: about 70%
Context
The work shows how microscale 3D printing can validate optical geometries made from accessible materials before transfer to scalable processes, with potential for more efficient low-light and multispectral sensors.
