# Smart Adhesives with Multilevel Security Features for Real-World Anticounterfeiting Applications

## TL;DR

This paper introduces a new type of adhesive with hidden security features to help prevent counterfeiting in manufacturing and publishing.

## Contribution

The study introduces adhesives with multilevel security markers that are functional and verifiable for anticounterfeiting purposes.

## Key findings

- Hot melt adhesives with IR emissive and up-conversion green phosphors maintain bonding properties while adding security features.
- The adhesive emits greenish-yellow and red light under specific laser illumination, detectable with filters or IR cameras.
- The multisecure glue provides bright green and pink emissions along with IR signals, offering tamper-resistant verification.

## Abstract

Counterfeiting in the manufacturing and publishing industries
poses
serious threats, including brand damage, financial losses, compromised
quality, and infringement of intellectual property rights. Although
existing anticounterfeiting technologies like RFID tags, QR codes,
holograms, and blockchain offer protection, increasingly advanced
counterfeiting methods challenge their effectiveness. Adhesives, despite
being essential in manufacturing and bookbinding for their bonding
and durability properties, remain underexplored as anticounterfeiting
tools. This study presents a novel approach by developing glue formulations
embedded with multilevel security markers for real-world applications.
Hot melt adhesives are integrated with infrared (IR) emissive and
up-conversion green phosphors, offering covert yet verifiable security
features while maintaining the adhesive’s key functional properties,
including melting point, viscosity, and bonding strength. Under a
980 nm laser light, the secure adhesive exhibits greenish-yellow and
red emissions, when viewed without and with a 610 nm band-pass filter,
in addition to IR emission at 1020 nm under a 340 nm UV light, detectable
by IR cameras or readers. The multisecure glue shows bright green
and pink emissions upon a 980 nm illumination along with IR signals
similar to the secure adhesive. These hidden yet easily verifiable
features provide a promising, tamper-resistant solution to counterfeiting,
particularly for book authenticity, enabling discrete verification
by authorized users while remaining undetectable to counterfeiters.