Researchers combine piezoelectric thin film and metasurfaces to create lens with tunable focus

https://phys.org/news/2022-02-combine-piezoelectric-thin-metasurfaces-lens.html

"thin-film PZT film, which allows the PZT to move the metasurface when a voltage is applied... placed a second metasurface lens after the MEMS-metasurface. Varying the separation distance between the lenses through MEMS displacement allows researchers to tune the focal point of the lens doublet... applying 23 volts allowed the PZT membrane to move the metasurfaces 7.2 microns, producing a focal length change of around 250 microns"