Fast-response microlens array fabricated using polyvinyl chloride gel

A droplet array which can function as a microlens array (MLA) is prepared by filling a small amount of polyvinyl chloride (PVC) gel into a polymeric cavity. The apex distance of each droplet decreases gradually as the applied DC voltage increases. The lens surface profile presents a spherical shape during actuation. By applying a voltage from 0 to 250 V, the focal length of the MLA changes from 2.75 mm to 3.15 mm and the measured total response time is 360 ms, which is lower operating voltage and much faster than that previously reported. The proposed MLA is free from gravitational effect, shaking, and vibration. It has potential applications in imaging, beam steering, biometrics, sensing, and electronic displays.