Harpreet Thandi and Ashley Carley
The word robot comes from the word ‘robota’ meaning forced labour in Czech. Traditionally robots are solid machines able to carry out tasks and help humans. This is now changing as the exciting new area of ‘soft robots’ is developing, where robots are made from materials such as silicone, plastic, rubber and mechanical springs. Merging soft and solid robotics could make robots more versatile and functional.
Robots that already exist bare a resemblance to humans and even other animals. In 2007, after her dad caught her a live octopus, Professor Cecilia Laschi of the BioRobotics Institute at the Sant’Anna School of Advanced Studies in Pisa, Italy, built her own.
Multiple octopi prototypes have been developed with tentacles made from wires and springs which can recreate a tentacle’s natural motion. Each tentacle can bend, stretch, curl, and behave in a very lifelike way.
These robots could be used for marine research projects and even exploring unknown areas of the ocean. This is an amazing opportunity to understand more about marine life, biology, and evolution. After all, we know less about the ocean than we do about space.
The biggest challenge is to get the robot’s ‘arm’ to curl, scrunch and stretch. An octopus’ longitudinal muscles shorten or bend when they contract. To mimic this, springs in the constructed ‘arms’ bend and then return to their original size.
By having a combination of wires inside the ‘arm’, it can bend around a hand. Imagine if, in the future, a soft robot could locate humans in an emergency, remove rubble and rescue survivors. This technique could work on land or in the water.
But this isn’t the only soft octopus in development. The ‘Octobot’ is the world’s first totally soft-bodied autonomous robot. It propels itself using its rubbery legs, half at a time, in a movement powered by gas from an internal chemical reaction.
This new area of robotics has many products in their prototype stage, currently. There are some limitations due the ‘softness’ of the designs; their motions are often unpredictable. The Octobot is relatively floppy and needs improving to a point where its movements are precise and responsive to its surroundings. Practical tests are needed to prove they are durable.
Soft robots may even be able to aid the human body in medical contexts. Soft robots can get into small spaces and even perform surgical operations, although non-toxic substances are required if the robotics are intended for use in the body.
There are many other applications that are not water-based. One invention, the ‘gripper hand’, has a variety of features that change depending on the size, weight, and slipperiness of the gripped object. The robotic hands could function in shops and bars, handling slippery bottles, boxes and bags, and be integrated into manufacturing machines and production lines.
The soft nature of this design could improve on the functionality, flexibility and dexterity of the present technologies. The hands can grip objects of any shape, from mushrooms and strawberries to bottles, demonstrating both delicacy and strength like the octopus model. This is different from the force and feedback systems that we had before.
At Harvard University’s Biodesign Lab, a new wearable robotic suit has been developed; an important movement for soft robotics. This ‘superhero’ suit has advantages over conventional exoskeletons – or Exosuits – which are uncomfortable and ill-fitting.
Exosuits allow heavy loads to be carried over long distances. The new Exosuit is constructed of nylon, polyester and spandex, making it more comfortable. Additionally, there are position and acceleration sensors for monitoring gait. A further development will involve swapping these with ‘stretchy’ sensors for a softer, more comfortable experience.
A new robotic fabric moves in response to an electric current. Shape-memory alloy coils are sewn in and can compress by 60%. These alloys track the fabrics movements. The fabric consist of stretch-sensitive silicone filaments that contain liquid metal.
The technology could be put on a sleeve to help injured, elderly or disabled people with their movement. The robotics also have various applications for space technology.
Soft robotics have many advantages: the technology is relatively cheap, strong, flexible, versatile, and able to fit into small spaces.
However, there are some problems and limitations. Soft robotics have not been fully tested in an industrial environment, they haven’t undergone in-depth strength tests and they still need to be attached to a power source.