Inkjet-Printed Multiwavelength Thermoplasmonic Images for Anticounterfeiting Applications

Area of Science:

• Nanotechnology
• Materials Science
• Optics

Background:

• Thermoplasmonic nanoparticles enable heat generation upon light illumination.
• Multiwavelength imaging allows different heat patterns from a single image based on light wavelength.
• Current anticounterfeiting methods may lack robust security features.

Purpose of the Study:

• To develop a novel multiwavelength thermoplasmonic image printing process for anticounterfeit applications.
• To create secure, thermoplasmonic labels with encrypted information.
• To enable invisible authentication using near-infrared or infrared light.

Main Methods:

• Inkjet printing of overlaid metal nanoparticles with different shapes.
• Fabrication of multiwavelength thermoplasmonic images.
• Illumination with specific wavelengths of near-infrared or infrared light.
• Reading of generated thermal patterns.

Main Results:

• Demonstration of instantaneous, large-area heat pattern generation from printed thermoplasmonic images.
• Successful generation of distinct thermal patterns from a single printed image by varying light wavelength.
• Validation of the invisibility of both the input light stimulus and output thermal signal.
• Confirmation of wavelength-selective photothermal effect for information encryption.

Conclusions:

• The proposed multiwavelength thermoplasmonic image printing offers a secure and robust anticounterfeit technology.
• Printed thermoplasmonic labels provide a fully secured inspection procedure.
• The combination of invisible illumination, thermal signal reading, and wavelength-selective encryption enhances security against counterfeiting.