Taking an example from the specialized footpads of insects, engineers from the University of California, Berkeley, used this principle to develop specialized robots that resemble insects. The principle of the footpads, which is known as electrostatic adhesion, was used to come up with an insect-sized robot that can move like insects.
Moreover, the agile dynamics of a cheetah is a unique feature that is included in the robot. This tiny insect-sized robot, with the strength and endurance of a cheetah, automatically makes itself adaptable in complex environments like unstable terrains and obstacle courses.
Interesting features of the microbot
The robot is created using material that contracts easily with the application of electric current. In the year 2019, a research team explained in a paper that this specific design can be used to construct an insect robot that can slither across a distance with a speed of about 1.5 miles/hour. This was also determined as a speed similar to that of cockroaches and also the fastest as an insect robot.
With the help of electrostatic footpads, an application of electric current can increase the force and make the robot glide through a surface in no time. It also makes the surface of the footpad sticky enough to stick to the ground while the rest of the robot can be rotated. Hence, these footpads allow the operators to fully control the movements of the robot which have a more advanced acceleration as compared to live insects.
Robots that lure in inspiration from nature
The insect robot that was designed at UC Berkeley has taken inspiration from the sticky footpads of insects, the build of a cockroach, as well as the agility of a cheetah. They managed to replicate multiple aspects of nature into one tiny robot. Similarly, Ollie, a mini-bot that does backflips was developed by Tencent Robotics. It has parallel legs and also a functional tail that helps the robot stand erect.
The researchers of UC Santa Barbara developed a soft burrowing robot that can dig up burrows imitating creatures like rabbits, southern sand octopus, and other burrowing animals. Researchers from Caltech and UIUC have made use of the functionality of bats to create the energy-efficient Bat Bot. This robot contains wings that it can flap for flight.
SpaceBok, a quadruped robot, was specifically designed for space exploration. With light-weight legs, hip and knee extensions, the space robot can perform flexible movements across difficult terrains.
Advancements in technology have come a long way now, but a century or two ago, there were hardly any technological aspects for developments. A major part of the technological devices that we now use regularly, have, in some form or the other, originated through inspirations from nature. For example, when birds were masters of flying, humans barely existed.
The airplane was invented only about a century ago and it was truly inspired by the flying nature of aerial creatures. We have so much to learn from nature, and some lessons are being witnessed every day.
Robotic research & technology has dived advancements only because of the innumerable lessons from nature. Several scientists solely rely on the actions of nature to replicate them in artificial devices. Adapting nature into robots has helped this field take a major leap towards the future.
Electrostatic footpads essence for the microrobot
When it comes to robots, the two most important things that one can look for is the feature of agility and control over its path. In a microrobot specifically, the lack of structural rigidity may hinder its characteristics in certain aspects. This, in turn, would lead to a lower performance overall. Electrostatic footpads work wonders for the maintenance of microbot rigidity and structural integrity.
The use of a piezoelectric film directed based on the structural resonance frequency of the robot, along with two electrostatic footpads helps with swift movements during rotations. A two-wire connection of both these features helps with the simultaneous functioning of these aspects in a microrobot.
With the help of these footpads, a centripetal acceleration of over 28 body lengths per square second was determined in an insect-sized robot, which is far better than that of a live insect like a cockroach. This was determined by directing the robot through a track that was 120 centimeters in length which it crossed within only 5.6 seconds.
Such results accomplished by the microrobot prove the superior performance achieved with the help of electrostatic footpads. They help to validate the importance of these footpads in small robots to ensure agility, enabling them to mimic real-life insects.
The tiny insect-sized robot can’t be squashed!
If you are squirmy at the sight of bugs, insects, and other crawlers, you will probably squish them on the spot. But what do you do when an insect-sized robot materializes before your eyes? Chances are, you will try to squish that too. But guess what? This insect robot probably won’t get affected by this and will continue to endure through its path. The functioning of the robots may not stop despite the weight on them.
A microrobot is highly useful when it comes to navigating through certain terrains for search and rescue missions. These are especially notable when it comes to fitting into places that no human or mammal can fit through. The small size of this robot does not hinder its strength which makes it a very suitable device for search operations and other accidents.
Professor Yichuan Wu of the University of Science and Technology in China expressed the major advantage that robots possess when it comes to navigating through a load of debris. Its robust structure not only helps it withhold any weight, but it also helps a great deal with performing tasks that were conventionally performed by larger robots. Believe it or not, the robot is almost the size of a postal stamp and structured like a narrow sheet.
This sheet is made up of a piezoelectric material which is called polyvinylidene fluoride. This is a unique material that expands or contracts with the application of a little electricity. This material was coated in another layer of an elastic polymer. This makes the sheet malleable, that is bend instead of expanding or contracting. Since the electricity caused the robot to move forward in a leaping motion, a front leg was added to straighten the field while bending.
All of this effort resulted in the creation of a microbot with astounding capabilities. At a speed of 20 body lengths per second, it can swiftly cross any surface, be it tubes, slopes, climbs, etc., and it can even carry a small load, probably the weight of a peanut. The average human weighs about 60 kg and an impressive thing is, this tiny robot can withstand this weight as well. The weight that it can withstand is approximately a million times more than its weight.
The similarities that this microbot has towards cockroaches are undeniable. Liwei Lin, a professor at UC Berkeley said that, unless you grind your foot over a cockroach until it dies, it may still move around. Similarly, when you step on the robot, you put a tremendous amount of weight on it, but it still survives.
Now, the robot is attached to a wire that carries an electric current to help with the oscillations. Attempts are being made to use batteries so the robot can have independent movement facilities. The addition of gas sensors as well as design improvement is being given attention to help the robot move through difficult surfaces with ease.
What went wrong with Micro bot’s first model?
The university engineers had designed a similar micro robot a while earlier, but it had a couple of issues. The current insect robot has most of these issues resolved which made the issues with the previous robot a learning opportunity for the newer, better version. According to Liwei Lin, the original robot was initially expected to be very efficient. With swift mobility, it could navigate through paths at a fast pace.
However, the main issue with this was that controlling the robot was hard. They found it hard to maintain the direction of the robot which made it move towards a random direction at any given point. This could have risen through manufacturing discrepancies which may have made the robot asymmetrical. The lack of symmetry, thereby, made it favor one side more than the other.
The agility of the robot was tested by directing it through a maze made of legos to simulate a rough terrain. All the while, the robot carried a gas sensor and was made to swerve time-to-time to mimic avoiding falling debris. The repeated experimentation with the design of the robot made them come up with a simple design. This, in turn, made it durable and hassle-free, amazingly able to withstand the weight of an average human being.
The attempts made to improve the size, agility, and durability of the robot made it grow into an effective tool to navigate through unreachable spaces. During emergencies like gas leaks, this robot can be used to find the source of the leak without any human intervention. It could also be used to move around in debris during calamities like earthquakes.
The team initially used a thin tethered wire to control the movements of the robot. Later on, they also managed to design a battery operation version. While testing it, they found out that the battery-operated robot efficiently moves around for up to 19 minutes, covering a distance of 31 meters. This was performed when the robot was carrying a gas sensor to serve its original purpose of coming to aid in times of crisis.
Recent challenges faced by developers while making small robots
The construction of a microbot, like a miniature device with the full potential of insects and cheetahs, is a challenging task in itself. However, the engineers’ team at UC Berkeley did face other challenges during the process of building the robot. One of the biggest challenges for them was to build a robot that was so small, but efficient, strong, and agile.
This small-scale robot had to be constructed in such a way that it would not let its size affect its power itself. They needed to design it considering the amount of power that it can hold at any particular time. While constructing larger robots you do not need to worry about the maintenance of power. This is because you can include large power systems like batteries in the robot itself.
Smaller robots cannot do this, and so, the researchers had to work on many ways to enable the robots to incorporate sensors and other electronic equipment with little power.
As we dive into the world of robotics, we witness several innovations which were once thought impossible for the human species. Natural as a sole inspirational source has worked wonders in helping researchers in devising unique robots. The field has a lot of scopes to make human life easier and also to explore surfaces that have not been met with the human eye.
Moreover, developers are quite inspired by what nature has to offer and try to incorporate it in their developments as much as possible. These include robots imitating the characteristics of bi-pedals along with a tail and incorporating features to help employ the robot as a tool for soil sampling, underground installations, erosion control mechanisms, and other similar tasks.
Robots now have the tolerance to operate in unfamiliar environments as well which suggests their endurance and animal-like resistance. They also possess potential uses in space as extraterrestrial robots in low gravity environments.