Humans, like every other animal, have a variety of senses — even more than the five “classical” senses. Part of the reason we have evolved those is redundancy, as one sense can serve as a backup for another that is damaged or is being obscured. But it’s also a matter of specialization; your sense of touch can often give you information that your eyes cannot. Robots today still often rely on just one or two kinds of sensors, and that can inhibit their ability to interact in our world. That’s why Cornell University’s Ph.D. student Patricia Xu has developed optical lace that can act like nerve endings and give robots a sense of touch.
There are many ways that you can equip a robot with touch sensors. The most basic is a simple button that is triggered when the robot touches something. But animals can feel thousands of individual points across their bodies, and it has been difficult to replicate that in any practical way by artificial means. This optical lace has managed to do so in a very novel way — at least on a relatively small scale. Even more importantly, it appears that the idea could be expanded to affordably cover large areas with touch sensors.
The setup has five major components types: an LED, an optical fiber that is always lit, a 3D-printed flexible lattice structure that acts like flesh, unlit optical fibers, and light sensors. The unlit fibers are positioned close to the lit fiber, and perpendicular to it. The other end of each unlit fiber as a light sensor. When force is applied to the lattice structure, it deforms and pushes the lit fiber closer to the unlit fibers. At that point, some light starts passing through the previously-unlit fibers, which can be registered by the light sensors.
Those light sensors can be as small and inexpensive as simple photoresistors, and can be monitored by any microcontroller. In this case, Xu is using an Arduino Uno board. The light levels also increase the harder the lattice is pressed, meaning varying degrees of pressure can be detected. This could allow robots to not only feel an object, but feel how hard they’re pushing on it. That is incredibly important for robots working with humans or delicate objects. The Organic Robotics Lab at Cornell has even created a startup company to utilize the optical lace for wearable sensors in clothing.
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Author: Cameron Coward