Fig. 1. (a) Fabrication process of the droplet-filled convex lens array. (b) Photo of the fabricated lens array and the top-view microscopic image of the lens array.

Fig. 2. Sinking process of the silicone oil droplet.

Fig. 3. Sinking of the silicone oil droplet with a deviation from the center.

Fig. 4. (a) Relation of the droplet volume and the diameter of the droplet at the bottom of the PDMS without the mold. The designed holes are slightly smaller than the diameter of the droplet. (b) Focal length of the lenses made of silicone oil droplets with different volumes.

Fig. 5. (a) Focal length tuning of the lens array. Ray fan diagrams for analyzing the aberration of the lens made of a 6.5 μL droplet (b) without pressure and (c) with 16 N pressure. Blue, 486 nm; green, 588 nm; red, 656 nm.

Fig. 6. (a) Imaging system for evaluating the imaging performance of the lens array. Inset: the customized lens mount. The image array of the letters (b) before and (c) after the tuning. The contrast of the image formed by a lens (d) before and (e) after the tuning.