Description: Harvard University has made another breakthrough in biomimetic robotics, inventing the first fully automatic octopus bionic robot, "Octobot." This is the world's first fully flexible, fully autonomous, self-fueled, battery-free soft robot. It does not contain any rigid electronic components such as batteries or computer chips, and its movement does not require connection to a computer. With its soft and cute octopus appearance and its graceful dancing ability, it has caused a sensation and can be called a "net celebrity" in the robotics world.

　　Harvard University has made another breakthrough in biomimetic robotics, inventing the first fully automatic octopus bionic robot, "Octobot." This is the world's first fully flexible, fully autonomous, self-fueled, battery-free soft robot. It does not contain any rigid electronic components such as batteries or computer chips, and its movement does not require connection to a computer. With its soft and cute octopus appearance and its graceful dancing ability, it has caused a sensation and can be called a "net celebrity" in the robotics world.

　　Although it looks like a toy from a gift bag at a child's birthday party, the "Octobot" bionic robot undoubtedly represents an amazing advance in robotics technology. With further improvements to "Octobot," it is expected to be used in the future in many fields, including ocean exploration and rescue, seawater temperature detection, and even military reconnaissance.

　　

 

　　To help everyone better understand how scientists created the "Octobot" soft robot, DT Jun visited Jennifer Lewis's laboratory at Harvard University.

　　Without further ado, let's illustrate the manufacturing process of "Octobot":

　　

 

　　Researchers weigh the silicone mixture for making the body of "Octobot"

　　

 

　　Researchers prepare platinum metal ink for 3D printing

　　

 

　　A custom-made octopus-shaped mold used to construct the body of "Octobot".

　　

 

　　"Octobot"'s center is a flexible microfluidic chip, which serves as the robot's "brain" and controls the movement of all eight tentacles.

　　

 

　　First, pour the silicone mixture into the octopus mold to cover the chip.

　　

 

　　Then, the 3D printer prints two lines of ink in the silicone resin: platinum metal ink reacts with the "fuel" hydrogen peroxide to generate gas that drives the movement of the robot's tentacles; another ink serves as a sacrificial layer, evaporating during the baking process to create hollow channels inside the robot's body for gas circulation.

　　

 

　　The complete set of tools and molds used to make "Octobot." Researchers tried over 300 times before successfully achieving the autonomous movement of "Octobot".

　　

 

　　A detailed close-up of the microfluidic chip implanted in the center of "Octobot"'s body.

　　

 

　　Equipment for making the octopus-shaped mold

　　

 

　　Usually, the "Octobot" body is colorless, sometimes using some eye-catching dyes to indicate the structure.

　　

 

　　The different colors shown here indicate the pathways of gas through "Octobot," used to alternately control its four tentacles to help it move. The "Octobot" robot is approximately 2 inches long.

　　

 

　　This picture was taken for fun; "Octobot" can glow in the dark.

　　Ryan Truby, a graduate student in the lab, said, "All parts are custom-made." The research on the materials for the "Octobot" soft robot was conducted in this lab, while the octopus-shaped mold and microfluidic chip for "Octobot" were developed by Robert Woods' lab. The materials used to make "Octobot" are commonly used in many microfluidic labs, but researchers tried over 300 experiments before getting the optimal "recipe".

　　First, the researchers place the microfluidic chip into a custom-made octopus-shaped mold; then, they inject a silicone (polydimethylsiloxane) mixture into the empty mold to cover the chip; finally, the researchers use a 3D printer to print two lines of ink in the silicone material, and then bake it for four days. Baking will seal the entire octopus shape and cause one of the two printed inks to evaporate, leaving only hollow conduits, which are ultimately used to allow air pressure to flow through and control its movement.

　　When it comes to robots, most people first think of images from movies like "Terminator" or "Transformers." In real life, most "robots" are indeed made of metal. However, more and more scientists are now interested in highly flexible "soft robots".

　　Soft robots have many advantages. Their manufacturing process is simple, they can be 3D printed, and the materials are relatively inexpensive. In addition, due to their high flexibility, they can play a unique role in narrow working environments.

　　However, until now, all soft robots have had a major problem: the power supply and control parts usually need to be external to ensure the overall flexibility of the robot. Therefore, when moving, the robot will drag long tubes or wires, seriously affecting its "freedom" of movement.

　　"Octobot" cleverly solves this problem. While maintaining flexibility, it integrates everything needed, including the actuator, control system, and functional system, so it can move completely "freely".

　　

 

　　Logic circuits are similar to circuit boards and can automatically control power.

　　The core key to solving this problem lies in how to build a flexible energy supply and power output system. The engineers at Harvard University gave the following answer—we don't use batteries, but directly use "fuel".

　　

 

　　The upper part of the overall drive unit of the octopus robot's internal reaction chamber, and the drive process within a tentacle. Shows the principle of microfluidic control technology injecting and draining liquid.

　　So, although "Octobot" looks very soft and cute, its body is actually equivalent to a pneumatic conduit, and its movement is essentially controlled by air pressure.

　　To achieve the autonomous movement of "Octobot," the researchers used a common hospital disinfectant—high-concentration hydrogen peroxide (chemically known as hydrogen peroxide). Scientists use a 50% concentration of hydrogen peroxide aqueous solution as fuel and platinum metal as the engine (actually a catalyst; to achieve a better catalytic effect, platinum metal powder is actually used).

　　

 

　　50% mass ratio hydrogen peroxide rapidly releases oxygen under the catalysis of platinum metal powder

　　Researchers pump hydrogen peroxide through a tube into the internal chamber at its center. It then comes into contact with a platinum wire, triggering a chemical reaction that produces gas. This gas expands and passes through a microchip called a microfluidic controller, driving the movement of the "octopus'" tentacles.

　　The gas is released alternately, controlling the up and down movement and swimming of half of the "octopus'" tentacles, making it appear to dance. It is claimed that with one milliliter of hydrogen peroxide fuel, the "octopus" can move for approximately eight minutes.

　　However, the "octopus" is far from perfect. Currently, the use time of "one tank" of fuel is approximately 4-8 minutes, and the robot's ability to autonomously turn is almost zero.

　　

 

　　Image of the microfluidic logic circuit inside the octopus robot. Source: Harvard University

　　Currently, scientists are creating "octopuses" of different sizes to determine the optimal size and proportions of the body parts. In addition, extra sensors will be added to allow the robot to sense its environment autonomously, enabling it to automatically avoid obstacles.

　　In fact, the design of the "octopus" intentionally follows minimalism, simply to demonstrate the complete ability to create this new type of soft robot. However, despite lacking sensing and programming capabilities, the "octopus'" completely flexible and fully autonomous movement characteristics are already stunning.