Figure 1.

Nanolens formation and imaging. (a) Artistic 3D rendering of the bead and nanolens. (b) As liquid condenses on the substrate, the lens surrounding a spherical nanoparticle thickens and changes shape. (c) Condensation of PEG is performed by suspending the substrate over a heated pool of liquid PEG in a closed chamber. (d) The nanoparticle sample with vapor-condensed nanolenses is imaged using an ultrawide field of view lens-free holographic on-chip microscope. (e, f) The condensation and imaging steps are integrated into a single field-portable device, such as the prototype shown here in schematic (e) and photograph (f). This portable device could be used in field settings for both the creation and simultaneous imaging of vapor-condensed tunable nanolenses.