Page 54 - REVISED 113

INNOVATION PROJECTS Variable focus liquid-lens for
IIT DELHI smartphone camera

Dr. Supreet Singh Bahga, Roshan Patra, Shivam Agarwal, Priyanshee
Palriwala, Kanuraj Anand, Mohit Singh,
IIT Delhi

The majority of smartphones in the market do not have optical zoom feature as integrating an assembly of fixed focal
length would increase the size and weight of the device. We have developed a bio-inspired deformable liquid lens
(shown in Figure 1) and integrated it with a smartphone. Our liquid lens uses two immiscible liquids as the refracting
media. The interface separating these two liquids is pinned at the sharp edge of an aperture, as shown in Figure 1.
As the screw in bottom chamber is moved in or out, the curvature of the interface changes. The lens power can be
positive or negative depending upon the interface curvature as shown in Figure 2. Unlike conventional optical
systems that require varying distance between fixedfocal length lenses, the liquid lens can give same functionality by
varying the curvature and eliminating relative movement between the lenses. The lens was integrated with a
smartphone and a variety of images were captured. Figure 3 shows an example photograph by using the liquid lens
as a zoom lens on a smartphone. We also characterized the response time of lens using high speed imaging.