Swiss researchers develop edible robot
Swiss researchers have developed a robot that is edible. It could be used in medicine or the environment.
Principle of operation of the edible soft robot
(Image: EPFLLIS/Screenshot: heise medien)
Being edible is not exactly a skill that comes to mind when thinking about a robot. Yet, a team from the Swiss Federal Institute of Technology Lausanne (École polytechnique fédérale de Lausanne, EPFL) has developed a robot that can be fully digested, including its energy storage and actuators.
The robot is a so-called soft robot, meaning it is made of a soft material. Such a robot moves, for example, by pumping air into or out of chambers in its body. This deforms the robot, thus generating movement.
Building an edible body for a soft robot is simple: an edible material, such as gelatin, can be used. The tubes between the chambers are also made of this. The team from the Laboratory of Intelligent Systems, led by Dario Floreano, has found a solution to ensure that the power supply and actuation are also digestible and do not lie heavily in the stomach.
Empfohlener redaktioneller Inhalt
Mit Ihrer Zustimmung wird hier ein externes YouTube-Video (Google Ireland Limited) geladen.
Ich bin damit einverstanden, dass mir externe Inhalte angezeigt werden. Damit können personenbezogene Daten an Drittplattformen (Google Ireland Limited) übermittelt werden. Mehr dazu in unserer Datenschutzerklärung.
As a propellant pumped into the chambers, the Swiss use carbon dioxide, which is stored in the form of baking powder in a chamber made of wax and gelatin. A second chamber of the energy storage contains liquid citric acid.
Energy from baking powder and citric acid
A membrane separates both substances. External pressure opens the membrane. The citric acid then drips onto the baking powder. Both react, producing sodium citrate and releasing carbon dioxide. All these substances are non-toxic and commonly used in the food industry.
The robot's actuator consists of two interconnected gas chambers on a slightly firmer base that bends under pressure. When gas is directed into the chamber, the actuator bends. However, this process must be performed multiple times succeeding. The sequence of bending and relaxing creates a kind of wriggling motion that can move the robot forward.
The chamber must therefore be emptied so that it can return to its original shape. For this, the researchers have developed a valve with a kind of snap closure. In its normal state, the valve is closed. If the gas pressure in the chamber increases, it opens and the gas can escape. If the pressure drops again, the valve snaps shut.
Videos by heise
Incoming gas then deforms the chamber again. The robot, which the team describes in the journal Advanced Science in the journal Advanced Science, bends about four times per minute. The battery supplies energy for a few minutes.
Why edible robots?
The question remains why a robot should be edible and digestible in the first place. Floreano's team dealt with this question last year – and provided several answers: If a robot is digestible, it is biodegradable. This means it could be used in the environment, leaving nothing behind after its operational life.
They see a practical application in medicine: the robot could be swallowed and then deliver healing agents to a specific location in the body. It would also not need to be retrieved, as the digestive system would break it down.
The last application mentioned by the roboticists refers to edibility: the robots could serve as food. They could, for example, move autonomously to the hungry in crisis areas, who could then eat them. Gimmicks in experiential gastronomy are also conceivable.
(wpl)
