Dynamic performance of a membrane-based variable focus lens with a large aperture.

Area of Science:

• Optics and Photonics
• Mechanical Engineering
• Materials Science

Background:

• Dynamic performance is critical for variable focus lenses.
• Limited research exists on the dynamic response of membrane-based variable focus lenses.

Purpose of the Study:

• To develop a mathematical model for the spring-damping phenomena in membrane-based variable focus lenses.
• To experimentally validate the dynamic response and natural frequencies of these lenses.

Main Methods:

• Developed a theoretical mathematical model for spring-damping phenomena.
• Utilized finite element analysis to determine first-order natural frequencies.
• Constructed a dynamic response experiment platform with adjustable optical apertures and a high-speed piezo stack actuator.
• Employed photodiode and laser displacement sensors to measure light luminance and membrane deformation.
• Collected data across various optical apertures (20-50 mm), pre-stretching ratios (200%, 300%), and driving frequencies (5-25 Hz).

Main Results:

• Finite element analysis confirmed first-order natural frequencies.
• Experimental results aligned with the mathematical model.
• The first-order natural frequency increased with decreasing optical aperture.
• Increased membrane stiffness also led to a higher first-order natural frequency.

Conclusions:

• The study provides a validated mathematical model for the dynamic performance of membrane-based variable focus lenses.
• The findings demonstrate a clear frequency-dependent characteristic influenced by aperture size and membrane stiffness.
• This research lays the groundwork for future investigations into optimizing the dynamic behavior of these lenses.