Surprisingly simple method makes a low-cost, tuneable liquid lens
May 4, 2025
By Imma Perfetto
Scientists from the Philippines have come up with a clever way to make adjustable water-based liquid lenses, which they say could be used as accessible and low-cost improvised lens systems in classrooms and laboratories.
“This was inspired by the natural shape of a water droplet on a flat surface, which resembles a plano-convex lens,” write the researchers in a paper describing their the method in the journal Results in Optics. “We vary the size and curvature of the droplets by changing the droplet volume, resulting in a variable focusing effect.”
Traditional glass lenses have a set curvature, so they bend light in a characteristic way. Only by stacking and altering the spacing between its lenses can the focal length of a camera or microscope be altered.
But liquid lenses can be adjusted without any moving mechanical parts, which means they can be small and light. This is often achieved by manipulating the shape of a sealed pocket of liquid – using pressure or electricity – to alter the way light refracts through it, and therefore its focal length. But traditional approaches to fabricating these dynamic liquid lenses are often complex and expensive.
More:
https://cosmosmagazine.com/science/physics/low-cost-tuneable-liquid-lens/