When we think of robots, we often immediately consider power sources, or at the very least, batteries – the things that provide energy for them to operate. Unfortunately, batteries are not an optimal way to power microbots, or tiny robots weighing less than 1 gram.
This is because they are heavy, bulky, and require numerous wires and accompanying control systems. Therefore, instead of using batteries, engineers often turn to chemical fuel systems when constructing microbots, with energy that can be directly converted into kinetic energy to help the robots function.
In such a study, a team of engineers from the University of Southern California, USA, successfully created a robot powered entirely by alcohol. It is capable of climbing over complex terrains and carrying objects many times its own weight.
Unlike most modern robots that operate on electricity, this new robot uses liquid methanol as fuel. With its small size, the robot can perform many complex tasks in real-world applications.
The product, named “RoBeetle”, is an invention from the University of Southern California (USA). True to its name, RoBeetle resembles a beetle commonly found on green plants.
Small beetle robot powered by methanol – (Photo: GETTY IMAGES).
The robot is small, weighing only about 88 milligrams, and measuring a few centimeters long, similar to the actual size of a beetle. Its compactness also places it among the lightest and smallest robots currently applied in daily life.
Notably, RoBeetle runs entirely on methanol instead of using batteries. According to the scientific journal Science, this is considered one of the first robots to use liquid fuel, specifically methanol, as its energy source.
The biggest challenge for the team was how to store and convert energy within the compact robot design. They came up with the idea of creating an artificial muscle system that can expand and contract just like human muscles.
The muscle fibers are made from a nickel-titanium alloy. When the methanol fuel is burned, the heat causes the muscle to expand due to the thermal variability of nickel and titanium. The wires are coated with platinum powder to act as a catalyst for the methanol combustion process.
Robot powered by methanol – (Video: SCIENCE).
When the muscle wire heats up and contracts, small microvalves in the robot automatically close, stopping the combustion process and allowing the frame and limbs to move.
Conversely, when the muscle wire cools and expands, the valves open again to ignite the fuel, starting a new cycle of movement. This process repeats until the fuel is exhausted.
Dr. Xiufeng Yang from the University of Southern California, the lead researcher, stated that this robot can carry loads up to 2.6 times its own weight. With a fuel tank of about 95 milligrams, RoBeetle can operate for 2 hours.
According to the research team, the robot can work flexibly across various terrains. It can easily climb slopes, crawl over surfaces such as soil, concrete, or glass…
Robot can move on various terrains – (Photo: SCIENCE)
Dr. Ryan Truby, a robotics expert at the MIT Research Institute, believes that RoBeetle represents a significant milestone in the technology of producing small and micro-scale robots. “RoBeetle will drive advanced devices for robots in the future,” Truby stated.
With RoBeetle, the practical applications are quite diverse. The robot can be used to inspect the quality of constructions, perform search and rescue operations in emergencies, or in agriculture, it can assist in the artificial pollination of plants.
