Soft Robots: Flexible in Form and Function

When most people think of the field of robotics, certain images come to mind: complex, Terminator-like humanoids, some sort of contraption on wheels, or a droid from Star Wars.  However, some of the most recent discoveries in robotics have occurred in the relatively unknown subfield called soft robotics, which involves automated machines made out of non-rigid parts.

Recently, researchers at Harvard University have created one of these robots, a full scale octopus robot with eight legs affectionately dubbed the “octo-bot” , all powered by gas that inflate and deflate its limbs.  By controlling a reaction involving hydrogen peroxide and platinum and changing the flow of the gas produced, certain limbs can be moved, allowing the robot to move.

Although the robot’s functions are limited and only possesses abilities that rigid robots can do much better, its development is important since it is one of the first soft robots to rely entirely on soft components, containing no circuit boards, wires, batteries, or any other rigid electronic components.

This field of soft robotics was actually not considered an official branch of science until 2010, when a scientific journal (aptly named Soft Robotics, or SoRo for short) was established for the purpose of publication of research papers.  However, there was not much progress or research done in this field, which at that time, was even more unknown than it is now.  

Later, in 2013, the Institute of Electrical and Electronics Engineers Robotics and Automation Society (IEEE RAS) established a committee dedicated to this field to further facilitate international discussion and since then, there have been a noticeable growth in soft robotics research.   One of the earliest projects done by scientists at the Italy Institute of Technology in soft robotics was the simulation and prototyping of a single octopus arm.  

From that single component, scientists then worked on combining multiple components of soft robotics into one.  Before the octo-bot was in development, more basic organisms were modeled, like a fish made by MIT engineers.  The curved, flexible nature of fish’s bodies that allow them to move smoothly through the water is impossible to replicate without soft robotics.

In the case of the fish, the inflation and deflation of air affect the curvature of the fish.  By altering the amount of air as well as the frequency of the inflation, the scientists were able to control the robot’s speed and direction of the robot.  They hope to place this robot in a natural habitat and collect information on the real life organism it’s supposed to represent.

These two robots, the fish and the octopus, were meant as stepping stones for the final goals of soft robotics, which as one may guess, mostly involve biomedical applications, since soft robots are able to simulate human touch or explore the innards of the human body without permanently displacing internal organs, which most people prefer.  

One such biomedical application is the surgery probe developed by roboticists at King’s College London, who have created a three-segment arm that utilizes chambers like the octo-bot that can be rotated and moved in an almost infinite amount of configurations within its range.  Traditional probes using a rigid exoskeleton and components can only be used in specific areas of the body, since there are some angles or openings that are unreachable without a large risk of injury.

The arm is split into three separate air chambers, and by calculating specific pressures at which the arm could bend at certain positions, the surgeons using this machine would be able to reach and take video of any area within a certain radius.  In addition, the flexibility of the robot enables it to squeeze between organs if necessary without causing much discomfort.  If a rigid robot attempts the same procedure, there is a high risk of puncturing these organs, causing permanent damage.

However, there are many other applications as well, like in the agriculture and retail industry, encouraging companies like Soft Robotics Incorporated to invest money into research,  where robots utilizing this technology are capable to “grasp fresh produce, electronic components, consumer goods, and clothing, among other objects, all with a single device”.  With rigid robots, separate machines would have to be made in order to effectively hold objects of various shapes, but this problem is rendered obsolete since soft robotics allows for contraptions that can easily adapt and mold themselves around different objects in various environmental factors.

The lovable Baymax, from Big Hero Six (Flickr/Jorge Figueroa)

Like most other technology, soft robotics has begun to gain presence in pop culture.  

Around 2011, Disney researchers visited a soft robotics lab at Carnegie Mellon University for inspiration for their movie Big Hero 6.  (Fun fact: One of the professors in the movie is voiced by a Carnegie Mellon alumnus.) They were inspired by soft robots that was targeted toward the health industry that aimed to have physical human interactions and in the process created Baymax, a lovable robot.  It didn’t take co-director Don Hall long to make a decision. “The minute he showed me [the] inflatable arm,” Hall said, “I knew we had our huggable robot”.

Evidently, the young field of robotics has come a long way from its humble beginnings.  Starting from just a simple device that could only contract and expand evolving to a medical device that could provide more accurate screening, developments in this field definitely seem to be exponentially increasing.  Along with quantum computing, artificial intelligence and genetic engineering, soft robotics has great potential to be one of the next “big things” of science.


Cover image: Lori Sanders/Harvard University