Bionic humans may be a popular trope of science fiction, but research at the University of California San Diego has brought us one step closer to machine-enhanced vision, Cyborg-style.
Writing in the journal Advanced Functional Materials, a team of soft material mechanics led by Shengqiang Cai describe the science behind a robotic lens designed in a proof-of-concept exercise. Blink twice to zoom in. Repeat to zoom back out. Turn your eye to the left (or right) and the lens will follow.
The new lens embraces the strengths of soft robots (or soft machines). These are robots made of highly compliant materials that mimick the behavior of living things. For example, you might have a soft gripping machine that can grasp objects as fragile as a raw egg – a task that would be more challenging for a conventional gripper made of a harder material. In this case, the soft robot mimics some of the mechanisms of the human eye.
According to the study authors, most soft robots are controlled manually or using pre-written code, but the robotic lens is different. It uses a novel human-machine interface controlled by eye movements and the electrooculographic signals that are produced as a result.
Even when your eye is at rest, a steady electrical potential exists between the cornea and Bruch's membrane. This electrical potential can be measured whenever you move your eye or blink, and it is these measurements that manipulate the robotic lens.
The lens itself is made out of salty water (or saline), which is encased in two electroactive polymer films and is controlled by five electrodes placed around the eyes that detect the eyes' electric potential. This allows the lens to expand and reduce in thickness if and when an electrical potential is detected, effectively allowing the user to zoom in and out just by blinking. And because the lens is made from soft materials, the relative change of focal length may be as large as 32 percent – which makes for a pretty impressive zoom feature.
The design hasn't been fully perfected – in its current form, it cannot move diagonally, only vertically and horizontally, for example. It can also be vulnerable to errors in movement recognition, which can result in activity beyond what the user intended (or nothing at all). But its potential is exciting. Because the electrical potential exists without vision, it could one day be used as a visual prosthesis, as well as in adjustable glasses or remotely-operated robotics.