Shear flow at openings and hydrophobic sliding at gaps: A method for fabricating deformable microlenses by extracting cavities from a liquid bath

A novel approach for fabricating deformable microlens arrays using template-induced self-assembly technology is introduced. By utilizing shear flow at cavity openings and hydrophobic sliding at interstitial gaps, this method achieves precise liquid microlens formation without the need for complex mechanical systems. The process employs a template immersed in a glycerol bath, where interfacial forces enable the pinning of liquid droplets within specific microcavities. A combination of theoretical modeling and finite element simulations was used to investigate the effects of cavity radius, pulling speed, and static contact angle on microlens liquid height. Findings reveal that larger cavity radii and higher static contact angles enhance liquid height. However, increased pulling speeds initially raise the liquid level before a subsequent decrease. Experimentally, uniform microlens arrays were successfully fabricated, demonstrating consistent surface shapes with the liquid level height of 43 μm and remarkable imaging tunability under thermal stimuli, achieving a 2.22-fold focal length expansion. This work advances the understanding of droplet manipulation and offers promising applications in microfluidics, optical systems, and surface engineering.