Positioning Adhesives for Active Alignment

Active alignment is a high-precision method used during the assembly of optical systems, wherein lenses and sensors are dynamically adjusted in real time to achieve optimal optical performance before the adhesive is cured. This process is essential for unmanned vehicles that rely on compact, integrated camera modules and sensor arrays for navigation, surveillance, mapping, and autonomous operation.

In the context of unmanned aerial vehicles (UAVs), unmanned ground vehicles (UGVs), and autonomous underwater vehicles (AUVs), consistent image quality and sensor accuracy are vital. Active alignment enables precise optical alignment by adjusting the positioning of components, such as lenses, image sensors, and filters, until the desired optical metrics are achieved. Once aligned, optical adhesives are cured to lock components in place with high mechanical stability.

Table of contents:

• What is Active Alignment?
• Applications in Unmanned Systems
• Role of Adhesives in Optical Alignment
• Types of Optical Adhesives Used
• Benefits of the Active Alignment Process
• Leading Developments in Active Alignment Adhesives
• Ensuring Accuracy & Quality

Active Alignment Adhesive by Dymax

What is Active Alignment?

Active alignment differs from passive assembly methods by incorporating real-time feedback during the alignment process. Automated optical alignment systems use vision-based techniques to measure optical parameters and iteratively adjust the position of each component to within a fraction of a micron. This level of precision is critical when assembling compact camera modules that must maintain focus and field of view across wide temperature and vibration ranges typical of unmanned vehicle deployments.

Applications in Unmanned Systems

Unmanned systems often operate in dynamic, harsh environments where small misalignments can significantly impact performance. Active alignment ensures optimal lens positioning for camera modules used in object detection, terrain mapping, obstacle avoidance, and target tracking. The approach is also used in LiDAR systems, optical fiber arrays, and other photonic assemblies where beam direction and focus are key to performance.

Role of Adhesives in Optical Alignment

Camera Module Adhesive by Dymax

Specialized optical adhesives used in the active alignment process must meet stringent criteria for viscosity, cure speed, thermal stability, and dimensional consistency. These adhesives, usually called positioning glue or precision positioning adhesive, are typically UV-curable or light-cured to allow for rapid setting after alignment is completed. The choice of optical bonding adhesive affects not only the mechanical integrity of the module but also its thermal and optical stability.

Some adhesives are tailored to maintain performance across thermal cycles, shock, and vibration. Others support automated dispensing and fast curing to fit into high-throughput production lines for unmanned system optics. These active alignment adhesives must remain dimensionally stable after curing, ensuring no shift in the lens or sensor position over time.

Types of Optical Adhesives Used

There are various types of optical adhesives suitable for active alignment, including:

• UV-curable adhesives: UV and light-curable adhesives are preferred for their rapid curing time and minimal thermal impact on sensitive components.
• Epoxy-based adhesives: Offering high bond strength and resistance to environmental factors.
• Hybrid adhesives: Combining benefits of multiple chemistries for specific performance requirements in unmanned applications.

Each type is selected based on the specific optical module design, alignment method, and environmental performance needed.

Benefits of the Active Alignment Process

The active alignment process ensures a consistently high manufacturing yield while maintaining the tight tolerances required for modern imaging systems. In unmanned vehicles, where space is limited and functionality must be optimized, this process enables:

• Enhanced image clarity and sensor performance
• Reduced optical aberrations and misalignment artifacts
• Long-term mechanical and optical stability
• Compatibility with automated, high-throughput assembly processes

By integrating automated optical alignment with advanced adhesives, manufacturers can produce reliable and compact camera modules and equipment that withstand the rigors of real-world operation.

Leading Developments in Active Alignment Adhesives

Recent innovations in active alignment adhesives have focused on reducing cure times, improving outgassing performance, and enhancing compatibility with various materials. Some formulations support low-temperature or dual-cure systems, expanding their use in temperature-sensitive optical components. Advanced rheology profiles help with precise dispensing during micro-assembly, and low shrinkage ensures that alignment remains consistent after curing.

Suppliers in this category continue to innovate around adhesion performance, environmental durability, and integration with automated alignment platforms, making these adhesives indispensable for advanced optical systems in unmanned vehicles.

Ensuring Accuracy & Quality

Active alignment is foundational for assembling optical systems in unmanned platforms, ensuring accurate lens positioning and robust performance in challenging environments. When paired with high-performance optical adhesives, the process enables efficient production of camera modules and sensor assemblies with exceptional optical quality and stability.

Manufacturers of unmanned systems depend on active alignment adhesives to achieve the precision, durability, and throughput required by modern imaging technologies. As demands increase for higher resolution and broader functionality, the synergy between optical alignment technologies and adhesive engineering continues to drive innovation across the industry.