HomeProjectsRobotics and Advanced ManufacturingStructural Coloration of Metals

Structural Coloration of Metals

Project Quick Facts

Principal Investigator

  • Prof. GUO Ping

    Department of Mechanical and Automation Engineering

  • Funding

    Information and Technology Commission

  • Patent

    Provisional Patent


This project proposed a cost-effective and efficient machining technology for structural coloration of metals. Structural color from the grating structures produces an iridescent effect which changes its apparent color with different viewing angles. Unlike the commercial ultrafast laser ablation method, the proposed mechanical machining technology utilizes ultrasonic vibration to create controllable and variable micro-gratings on processed surfaces. Furthermore, the proposed process offers a feasible way to produce arbitrary optically variable colorful images with good resolution and high efficiency.


Problem to be solved:

Structural colors origin from the periodic surface micro/nano grating structures with nanoscale intervals. Generation of high-quality marketable structural colorized metallic molds should overcome the following challenges:

  1. Production of surface micro/nano grating structures with high efficiency
  2. Precise control the profiles and distributions of produced grating structures
  3. Minimization the cost of production


Structural colors of metal surface can be transferred onto the polymer film surface using the compression molding technology. The polymer film with structural colors have been widely employed in the product packaging, decoration and anti-counterfeiting fields.  Laser sticker and anti-counterfeiting labels with structural colors are the most common commercial products among them.

Target Users

package plant, security labels manufacturer

Uniqueness and Competitive Advantages:

The proposed mechanical process utilizes ultrasonic elliptical vibration texturing (EVT) technology to concurrently produce precise and controllable micro/nano grating structures during a shape operation, which has the following uniqueness and advantages:

  1. Do not involve any ultrafast laser system. (cost-friendly)
  2. The feasibility to create full pallet structural colors with high efficiency
  3. The feasibility to precisely control the grating profiles and distribution.
  4. The feasibility to produce arbitrary optically variable colorful images using structural coloration.

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