Polymer-hungry robots
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An elephant’s memory for plastic antsThe field of robotics is very popular nowadays. Many research laboratories in the field have stated that they draw inspiration from nature. |
Some of them even take this interest a step further by creating “monsters” that nature itself could not devise. Why copy the abilities of a single animal when you could mix at least two of them? That seems to be the line of reasoning followed by the German Festo which has developed a robotic arm directly inspired by an octopus tentacle and an elephant trunk. Like an elephant’s trunk, it can move in any direction and thanks to its suckers it is able to grip and lift almost any object up to a weight of three kilogrammes. The BionicMotionRobot’s arm is made up of three flexible segments actioned by pneumatic bellows made of an elastomer, a polymer that is both flexible and strong. Each of them is wrapped in a layer of synthetic fabric reminiscent of the muscle fibres of an octopus tentacle. Thanks to this structure, the arm is able to move in three directions at the same time and perform the same natural movements as its inspirations, the elephant and the octopus.
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Festo is no stranger to sensational developments. It first came to the general public’s attention in 2015 when it unveiled a robot that reproduced the anatomy and social behaviour of ants. It was quite a challenge because the 1.5 cm long robots had to be covered in electronics and sensors of all kinds in order to function. The researchers naturally investigated plastronics, and in particular laser sintering: a technique used to inject the electronic components directly into the plastic parts forming the different parts of the ant robots’ bodies. |
Always in the news, the robots designed by Festo are the height of technology and often give pride of place to plastronics |
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Plastic fly’s eyesBiomimicry specialists are also fascinated by the eyes of the fly. With good reason, because the insects almost have a sixth sense giving them an extraordinary ability to dodge most things that come their way. Their eyes are made up of thousands of sensors that are sensitive to light, of course, but also to the direction and speed of moving “objects” in their immediate environment.
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As things stand, no camera is currently able to mimic the abilities of a fly’s eye. Yet, creating an artificial imitation of the organ could have significant consequences, in particular for blind people who could wear clothing equipped with such an eye. It would not enable to recover sight, but the technology could be used to create a vibrating signal when a moving obstacle is near. Drones used for rescue missions could also benefit from such a technology.
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The European Commission has financed this area of research. Various laboratories in Switzerland, Germany and France have joined forces in order to develop such a new eye. And it seems that they have been successful, as the brilliant consortium has created an artificial eye, named CurvACE, which is as effective as a fly’s eye. This marvel of technology is made up of three different layers: an optical layer made up of a set of highly-transparent polymer microlenses molded onto a glass base which focuses the light onto a second layer made up of silicon photodetectors. |
Artificially reproducing a fly’s eye could greatly improve blind people’s quality of life. The European Commission is financing research in various European laboratories and the initial results are promising. |
The final layer, a printed circuit board made from polyimide, a particularly heat-stable polymer, is used for interconnectivity. It will not find its way to the market anytime soon, but the researchers at the Ecole Polytechnique in Lausanne are already working on a prototype cap for the blind.
Polymers play sorcerer’s apprentice
Polymers can be found at all levels of “biomimetic” research, including the extreme, those which design robots made from living cells and synthetic materials such as polymers. Researchers at the Harvard bioengineering laboratory in the United States have used rat cells, silicone and gold to create a robot taking inspiration from the ray. Halfway between biomimicry and bioengineering, the researchers based their model on the way a stingray moves by contracting its muscles to create mini whirlpools that carry it forward. The aim was to reproduce this very particular movement. To achieve this, they designed a robot measuring only a few centimetres in length made up of four layers: a layer of transparent polymer from the silicone family for the body, a gold skeletal structure, another layer of silicone, and nearly 200,000 genetically-modified rat heart cells. The cells are activated when exposed to light and serve to move the robot. According to the researchers, this artificial fish could help to improve knowledge about the way in which the heart pumps blood to the organs and to develop methods for designing and controlling heart cells in order to build an artificial heart in the future.
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Another American team based in Cleveland created a sea slug using muscles from the said gastropod. This new creature, which is both living and artificial, has muscles taken from the Californian sea slug which, as is the case with the stingray robot, are controlled by external electromagnetic fields. The muscles were inserted into a 3D-printed polymer shell that faithfully reproduces the body of a living slug. According to the team, hybrid or bionic robots are able to perform tasks that an animal or a robot could not perform alone. This type of “machine” could be used to explore environments contaminated by toxic leaks, or be used to search for the black box of an aircraft that disappeared at sea. |
This artificial stingray made from living cells and a polymer of the silicone family is a hybrid robot. It could be the prelude to the next generation of artificial hearts. |
This sea slug is also a hybrid. Its shell is made of a 3D-printed polymer that protects the robot’s living organs. |
Another American team based in Cleveland created a sea slug using muscles from the said gastropod. This new creature, which is both living and artificial, has muscles taken from the Californian sea slug which, as is the case with the stingray robot, are controlled by external electromagnetic fields. The muscles were inserted into a 3D-printed polymer shell that faithfully reproduces the body of a living slug. According to the team, hybrid or bionic robots are able to perform tasks that an animal or a robot could not perform alone. |
This type of “machine” could be used to explore environments contaminated by toxic leaks, or be used to search for the black box of an aircraft that disappeared at sea.
Real artificial intelligence still requires a world of progress in computing. Improved understanding of the role of synapses is one of the paths explored by a South Korean university. By creating nanometric wires from scratch, the researchers were able to reproduce their functioning at a very small scale. |
Finally, a team of researchers in South Korea claims to have successfully imitated the brain’s synapses, the small bridges that connect neurons to each other. Although the world’s most powerful computer has a computing power five times greater than that of the human brain, it is still unable to compete as its analytical capacity is far from comparable. This can be explained by the fact that living creatures have greater synaptic density than machines, and that such density remains impossible to reproduce artificially. |
However, research is moving forward and the team based in Kora successfully built a system comprising 144 synapses: a very low number compared to the human brain, but quite a feat! The system, which only measures a few square centimetres and which the electronics engineers have named transistor, is filled with polymer wires that mimic the synapses. Each wire measures between 200 and 300 nanometres, which is 330 times thinner than a human hair. In order to achieve that size and level of precision, the researchers all but had to invent a new polymer based on trichloroethylene and chlorobenzene which was then used as a material in a 3D printer entirely designed in the laboratory. This is a true revolution that could benefit the worlds of computer science and nanorobotics.
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