A bifocal compound liquid lens with continuous zoom based on selective wettability

Area of Science:

• Optics and Photonics
• Materials Science
• Microfluidics

Background:

• Traditional optical lenses often lack tunability and compactness.
• Liquid lenses offer potential for dynamic focal length adjustment.
• Achieving bifocal capabilities in liquid lenses presents unique challenges.

Purpose of the Study:

• To propose and demonstrate a tunable zoom bifocal liquid lens.
• To utilize selective wettability for precise droplet control.
• To investigate the modulation of focal lengths via applied voltage.

Main Methods:

• Fabrication of a bifocal compound lens using immiscible coaxial droplets.
• Selective wettability employed for droplet arrangement and stability.
• Electrical voltage applied to alter droplet curvature and focal properties.

Main Results:

• Successful demonstration of a tunable zoom bifocal liquid lens prototype.
• Short focal length varied from 15.46 mm to 17.47 mm.
• Long focal length ranged from 96.25 mm to 70.31 mm with 200 V.

Conclusions:

• The proposed liquid lens design enables tunable bifocal operation.
• Selective wettability is a viable method for controlling liquid lens geometry.
• The demonstrated focal length modulation confirms the lens's practical potential.