Light activation of 3D-printed structures: from millimeter to sub-micrometer scale

Area of Science:

• Additive Manufacturing
• Materials Science
• Smart Materials

Background:

• Three-dimensional (3D) printing allows complex structure fabrication.
• Four-dimensional (4D) printing adds responsive functions to 3D-printed structures.
• Light offers remote and selective stimulus for shape transformation.

Purpose of the Study:

• To provide a comprehensive review of light activation in 3D-printed structures.
• To highlight the potential of 4D printing for adaptive and deployable devices.
• To consolidate recent advancements in light-activated complex 3D structures.

Main Methods:

• Reviewing smart materials and shape-changing mechanisms in 4D printing.
• Analyzing the design and demonstration of remote light activation.
• Detailing photothermal activation mechanisms using nanomaterial composites.

Main Results:

• 3D-printed structures can transform shape via external stimuli like light.
• Light activation enables remote and selective structural changes in complex 3D prints.
• Photothermal activation using nanomaterial composites is a key mechanism.

Conclusions:

• Light activation of 3D-printed structures is a rapidly growing research area.
• 4D printing with light stimulus has broad applications in actuators, robotics, and photonics.
• This review covers light activation from millimeter to sub-micrometer scales.