Tag Archives: Robotics

New Requirements for Miniature Motors

Innovations in the field of robotics are resulting in the emergence of smarter and smaller robotic designs. Sensor technologies and vision systems use robotic applications in warehousing, medical, process automation, and security fields. Disruptive technologies are creating newer opportunities for solving unique challenges with miniature motors. These include the robotic market for efficient and safe navigation through warehouses, predictable control of surgical tools, and the necessary endurance for completing lengthy security missions.

With industries transitioning to applications requiring collaborative robotics, they need systems that are more compact, dexterous, and mobile. Tasks that earlier required handling by human hands are driving the need for miniaturized motors for mimicking both the capability and size of the hands that accomplished the work.

For instance, multiple jointed solutions representing the torso, elbow, arm, wrist, etc. require small, power-dense motors for reducing the overall weight and size. Such compact solutions not only improve usability but also improves autonomy and safety, resulting in faster reaction times due to lower inertia. Therefore, robotic grippers, exoskeleton, prosthetic arms, and humanoid robots require small, high-power density motors. Power density is the amount of power a motor generates per unit of its volume. A motor that generates greater amounts of power in a small package, has a higher power density. This is an important factor when there is a space constraint, or where a high level of output is necessary when a limited space.

Manufacturers can miniaturize motors with high power densities. Alternately, they can increase the capability of current designs. Both options are critical in reducing the space that motion elements occupy. High efficiency is necessary to obtain the maximum power possible from a given design. Here, BLDC or brushless DC motors and slot-less motor designs in combination with efficient planetary gearboxes can offer powerful solutions in small packages. Brushless solutions are flexible enough for engineering them to meet customer requirements like long and skinny designs, or short, flat, low-profile configurations.

Smooth operation and dynamic response can result in these miniature motors being dexterous and agile. Slot-less BLDC motors achieve this by eliminating detent torque, thereby providing precise dynamic motion with their lower inertia. Applications requiring high dynamics, such as pick-and-place systems and delta robots, must be able to accelerate/decelerate quickly and constantly. Coreless DC motors and stepper motors with disc magnets are suitable for applications requiring critical characteristics like high acceleration as they have very low inertia.

Ironless brushed DC motors with their high efficiency, are the best choice for battery-powered mobile applications to extend their operational life between charges. Several robotic applications now run on battery power, thereby requiring motors with high efficiency for longer running times. Other applications require high torque at low speeds, and it is possible to achieve this by matching the motor with a high-efficiency gearbox.

Some applications that are inhospitable to humans may need robot systems capable of enduring difficult environmental conditions. This may include tremendous vibration and shock. With proper motor construction, it is possible to improve their reliability and durability when operating under such conditions.

Handling Grippers

Material handling in industries is increasingly relying on grippers. Industries, ranging from automotive assembly to electronics manufacturing, all handle their materials with grippers. The increasing requirement for grippers is evident from the market being worth $100 million in North America alone today, with the number expectedly growing by 5% annually.

The sudden spurt in growth in the use of grippers can be attributed to the rise in robotics. This includes industrial robots taking on special tasks like handling increasingly complex workpieces. Designers now can take their pick from more types of grippers than before. However, even with the latest developments in robotics and gripper technology, picking the most suitable gripper for a specific application can be a daunting task.

The market today has a plethora of grippers including mechanical, adaptive, soft, magnetic, and vacuum types, with each type offering key design features and benefits. For instance, adaptive and soft grippers adapt themselves to the contours of the workpiece and are useful in various handling applications.

Mechanical grippers, both electric and pneumatic types, are popular for handling applications. Of these, the pneumatic types make up about 90% of the demand, as these tend to be lighter and more cost-effective compared to the electrical types. Being more suitable for harsh environments, pneumatic grippers have faster cycle rates and higher grip forces.

On the other hand, electric grippers offer their users better travel and force control along with greater precision. However, the presence of motors and other internal components in these grippers tends to make them heavier and increases their upfront costs.

Irrespective of being pneumatically or electrically operated, there are several design classes of mechanical grippers. For instance, parallel grippers have fingers that can pull directly apart. The most common among these is the two-finger parallel gripper. These make up more than 85% of the market for mechanical grippers. Another version is the three-finger gripper, and it can perform centering functions and handle round objects.

Other classes of mechanical grippers include the angular and radial versions. These typically have fingers that open at an angle. For instance, angular grippers open their fingers only to 30-degrees, while radial grippers can open their fingers up to 180-degrees, allowing them to handle workpieces of varying dimensions while being slower than angular grippers.

Selecting grippers for a specific application requires considering important factors. Depending on the nature of the workpiece, the designer must consider the gripping force required, the guiding strength of the jaw, and the type of the gripper itself. For instance, long gripper fingers require a long lever arm to exert greater torque on the jaws. There are flat finger designs that offer a friction-based grip for durable and bulky parts. On the other hand, handling slippery parts that require precision placement must use encapsulated designs.

Encapsulated designs have fingers with a profile shape matching the object they will handle. Usually, the fingers will be curved to hold a round object. This helps to retain the object in a specific position while preventing that part from dropping if the pressure is lost.

Meca500 – The Tiny Six-Axis Robot

Although there are plenty of robots available in the market for a myriad jobs, one of the most compact, and accurate robot is the Meca500. Launched by the Quebec based Mecademic from Montreal, the manufacturers claim it is the smallest, and most precise six-axis industrialist robot arm in the market.

According to Mecademic, users can fit Meca500 easily within an already existing equipment and consider it as an automation component, much simpler than most other industrial robots are. According to the cofounder of Mecademic, Ilian Bonev, the Meca500 is very easy to use and interfaces with the equipment through Ethernet. With a fully integrated control system within its base, users will find the Meca500 more compact than other similar offerings are in the market.

Mecademic has designed, developed, and manufactured several compact and accurate six-axis industrial robot arms on the market. Meca500 is one of their latest products, the first of a new category of small industrial robots, smaller than most others are, and ultra-compact.

The first product from Mecademic was DexTar, an affordable, dual-arm academic robot. DexTar is popular in universities in the USA, France, and Canada. Although Mecademic still produces and supports DexTar on special request, they now focus exclusively on industrial robots, delivering high precision, small robot arms. With their academic origins, Mecademic has retained the predilection of their passion for creativity and innovation, and for sharing their knowledge.

With the production of Meca500, a multipurpose industrial robot, Mecademic has stepped into Industry 4.0, and earned for itself a place in the highly automated and non-standard automated industry. With Meca500, Mecademic offers a robotic system that expands the horizons for additional possibilities of automation, as users can control the robot from their phone or tablet.

This exciting new robotic system from Mecademic, the Meca500 features an extremely small size, only half as small as the size of the smallest industrial robot presently available in the market. Meca500 is very compact, as the controller is integrated within its base and there is no teaching pendant. The precision and path accuracy of the robot is less than 5 microns, and it is capable of doing the most complex tasks with ease.

Applications for Meca500 can only be limited by the users’ imagination. For instance, present applications for the tiny robot include a wide range, such as animal microsurgery, pick and place, testing and inspection, and precision assembly.

Several industry sectors are currently using Meca500. These include entertainment, aeronautics, cosmetics, automotive, pharmaceuticals and health, watchmaking, and electronics. Users can integrate the compact robot within any environment, such as their existing production line or even as stand-alone system in their laboratories.

The new category of robots from Mecademic is already smaller, more compact, and more precise than other robots are in the market. Mecademic’s plans for the future include offering more space saving, more accurate, and easier to integrate industrial robots. They envisage this will enable new applications, new discoveries, new products, new medical treatments, and many more. Their plan is now to build a greater range of compact precision robots while becoming a leading manufacturer of industrial robots.

Robotics and Motion Control

Across the industrial space, automation is a growing trend in factory floors throughout the world. This is essential to improve the efficiency and production rates. When creating the automated factory, engineers may introduce a robotic system or implement a motion control system. Although both can essentially accomplish the same task, they have their own unique setups, motion flexibility, programming options, and economic benefits.

The Basics

A straightforward concept, motion control initiates and controls the movement of a load, thereby performing work. A motion control system is capable of precise control of torque, position, and speed. Motion control systems are typically useful in applications involving rapid start and stop of motion, synchronization of separate elements, or positioning of a product.

Motion control systems involve the prime mover or motor, the drive, and its controller. While the controller plans the trajectory, it sends low-voltage command signals to the drive, which in turn applies the necessary voltage and current to the motor, resulting in the desired motion.

An example of a motion control system is the programmable logic controller (PLC), which is both noise-free and inexpensive. PLCs use the staple form of ladder-logic programming, but the newer models also have human-machine-interface panels. The HMI panels offer visual representations of programming the machine. With PLCs, the industry is able to control logic on machinery along with control of multiple motion-control setups.

Robots are reprogrammable, multifunctional manipulators that can move material, tools, parts, or specialized objects. They can be programmed for variable motion for the benefit of performing a variety of tasks.

Most components making up the motion control system are also a permanent part of robots. For instance, a part of the robot’s makeup includes mechanical links, actuators, and motor speed control. The robot also has a controller, which allows different parts of the robot to operate together with the help of the program code running in the controller. Most modern robots operate on HMI that use operating systems such as Linux. Typical industrial robots take many forms such as parallel picker, SCARA, spherical, cylindrical, Cartesian, or a simple articulated robotic arm.

Robot systems also make use of drives or motors to move links into designated positions. Links form the sections between joints, and robots can use pneumatic, electric, or hydraulic drives to achieve the required movement. A robot receives feedback from the environment from sensors, which collect information and transmit it to the controller.

The Differences

While the robot is an expensive arrangement, a motion control system has components that are modular, and offer greater control over cost. However, motion controller components require individual programming to operate, and that puts a greater knowledge demand on the user.

Motion control systems, being modular, offer the scope to mix and match old hardware with the new. This facilitates multiple setups, with modular configuration ability, and applicable cost constraints.

With hardware differences between products decreasing rapidly, purchasing decisions are now mostly based on the software of the system. For instance, most modern systems are plug-n-play type, and they rely more on their software for compatibility.

How Good are Cobots at Welding?

The manufacturing industry has been using robots widely for several years as a replacement for the human laborer. Recent advances in this field are the Cobots or collaborative robots. They are called collaborative as their design makes them work alongside an individual as a part of a team rather than replacing the humans.

Cobots are good at operations and activities that cannot be fully automated. However, the process speed does not improve for activities such as workers ferrying parts backwards and forwards between themselves on the assembly line with the robots locked away in cages.

Manufacturers such as Ford are already on the cobot bandwagon, and the new robots could transform the way the industry works. The Ford factory has collaborative robots installing shock absorbers on vehicles on the production line along with humans. The cobots work with accuracy and precision, boosting the human productivity, while saving them valuable time and money.

At present, the industry uses four main types of cobots. They are the Safety Monitored Stop, Speed and Separation Monitoring, Hand Guiding, and Power and Force Limiting.

The Safety Monitored Stop is a collaborative feature used when the cobot works on its own, but sometimes needing assistance from an operator. For instance, in an automated assembly process, the worker may need to step in and perform an operation on a part that the cobot is holding. As soon as the cobot senses the presence of the human within its workspace, it will cease all motion until the worker leaves the predetermined safety zone. The cobot resumes its activities only after receiving a signal from its operator.

Speed and Separation Monitoring is similar to the Safety Monitored Stop, with the cobot operating in a predetermined safety zone. However, this cobot’s reaction to humans is different. The Cobot will not automatically stop because of the human presence, but will slow down until its vision detection system informs it of the location of the person or object. The Cobot stops only if the person is within a predetermined area, and waits for the proximity to increase before resuming its operations. This cobot is useful in areas with several workers are present, at it requires far fewer human interventions.

Although a Hand Guiding cobot works just as a regular industrial robot does, it has additional pressure sensors on its arm device. The operator can therefore teach the cobot to hold an object hard enough and to move it fast enough without damaging the object, while securely working with it. Production lines that handle delicate components find Hand Guide cobots very useful for careful assembly.

Power and Force Limiting cobots are among the most worker-friendly machines. They can sense unnatural forces in their path, such as humans or similar objects. Their joints are programmed to stop all movement at such encounters, and even reverse the movement.

As many skilled workers retire, and replacements are rare, the American Welding Society is working with Universal Robots, to produce a new attachment to their UR+ line of cobots with welding capabilities. The robot moves along the start and stop path of the desired weld, and welds only the specified stitch areas.

What is an i-Robot?

The level of CO2 in our atmosphere is increasing at alarming levels, affecting all life on Earth either directly or indirectly. For instance, it is related to global warming risks, reducing the quantity of ice in the polar regions, which in turn changes the level of seas all around as the ice melts. This has significant consequences on several human activities such as fishing. It also affects the submarine environment adversely, together with the associated biological sphere. For long, scientists have been monitoring the marine environment and studying the status of the seas.

However, the harshness of the marine environment and/or the remoteness of the location preclude many explorations under the sear by vehicles driven by the mother ship. Scientists are of the view robots could effectively contribute to such challenging explorations. This view has led to the development of Autonomous Underwater Vehicles or AUVs.

One such AUV is the Semi-Autonomous Underwater Vehicle for Intervention Mission or SAUVIM, and is expected to address challenging tasks as above. The specialty of SAUVIM is its capability of autonomous manipulation underwater. As it has no human occupants and no physical links with its controller, SAUVIM can venture into dangerous regions such as classified areas, or retrieve hazardous objects from deep within the oceans.

This milestone is a technological challenge, as it gives the robotic system the capability to perform intervention tasks such as physical contact with unstructured environment but without a human supervisor constantly guiding it.

SAUVIM, being a semi-autonomous vehicle, integrates electronic circuitry capable of withstanding the enormous pressure deep ocean waters generate. In general, it can operate in the harsh environmental conditions—low temperatures of the deep oceans—in a reliable and safe manner. Ensuring the effectiveness of such robots requires a high level of design and accurate choice of components.

As SAUVIM operates semi-autonomously, it needs huge energy autonomy. For this, Steatite, Worcestershire, UK, has introduced a new solution in the form of long-life batteries, ones capable of operating in submarine environment. These Lithium-Sulfur (Li-S) battery packs, a result of the first phase of a 24-month project, improves the endurance and speed of autonomous underwater vehicles when deep diving.

Primary advantages that Li-S batteries offer are enhanced energy storage capability to provide improvements in operational duration, despite being constructed from low-cost building materials.

The National Oceanography Center in Southampton, UK, completed the first phase of the Li-S battery project, after repeatedly testing the cells at pressure and temperatures prevailing in undersea depths of 6 Kms. According to the tests, Li-S cells can deliver performances similar to those at ambient conditions, while their effective Neutral Buoyancy Energy Density or NBED is almost double that offered by Li-ion cells used as reference. Life tests, performed on a number of Li-S cells demonstrate they can reach over 60 cycles with slow discharge, and 80 cycles with fast discharges.

The energy within an AUV is limited, which also limits its endurance. Therefore, to conserve the available energy, speeds of AUV are usually kept low at 2-4 knots. Therefore, to enhance or expand this operational envelope, it is necessary to increase the energy available within the vehicle, and the Li-S batteries do just that to increase the vehicles range and speed.

Computer Vision & Robotics in Farming

Robots are helping several industries ease labor concerns. This is increasingly so in today’s industrial environment, where the workforce is aging and work output decreasing for lack of efficiency. This includes agricultural fields in both the US and Europe, where the introduction of robots in fieldwork is helping to reduce current labor concerns. New farming standards brought on by natural and chemical resources is increasing the need for precision work, and robots and new technology is helping to alleviate that.

According to Dan Harburg, the design of traditional robots allowed them to perform only specific tasks repeatedly. Dan is with Anterra Capital, an agriculture technology venture capital firm from Amsterdam. According to Dan, robots for agricultural applications must be more flexible than those in automotive manufacturing plants are, as the former need to deal with the natural variation in outdoor environment and food products.

Accordingly, Anterra Capital considers investing in three major category areas in agriculture related to seeding and weeding, harvesting, and environmental control. Dan envisages each of these major categories would benefit from the introduction of advanced technology and robotics.

For instance, farmers get a two-fold benefit from spraying and weeding robots. First, these robots reduce the labor necessary for eliminating such mundane tasks. Second, by precise targeting of crops, the robots bring down the quantity of pesticides necessary to be sprayed. This allows farmers to save on labor costs and produce safer, healthier crops at the same time. For instance, see and spray robots from Blue River reduce agrochemical use by about 90%, as they use computer vision for targeting weeds.

Different technology companies have developed spray robotics. One among them is the Blue River Technology, a farm robotics start-up specializing in spray and weeding robots. According to Blue River, its tractors operate at 6-8 mph, covering 8-12 rows of crops simultaneously. Advanced vision systems on the tractors enable them to differentiate weeds from crops to provide direct targeting as it passes over them.

Autonomous robots from Naio Technologies use laser and camera guidance systems for navigating between rows of fruit s and vegetables autonomously, identifying different types of weeds. Oz, the robot from Naio, runs on four electric engines, working continuously for three hours before needing a battery recharge. Not needing human supervision, Oz follows rows of crops on the plot autonomously, to remove all weeds.

PlantTape, from Spain, offers a plant-transplanting robot that can plant seeds. The robot fully integrates the system of sowing, germination, and nursery care. This brings much higher efficiency as compared to that from conventional transplanting methods. The robot creates trays of tape for holding soil and seeds, with each tray holding nearly 900 plants. While pulling the tape from the tray, the automated robot tractor cuts the tape around each plant as it places the plant accurately in the soil. Farmers use PlantTape robots for planting tomatoes, onions, celery, cauliflowers, broccoli, and lettuces.

Although automation in harvesting crops is common, the variation in size, height, and color of the plants compounds the problem. They also require light pressure and touch for delicate picking. Vacuum suction robotic arms help in this area.

What is a Hygrobot?

In the future, tiny robots such as the hygrobot will be able to avoid the need for batteries and electricity to power them. Like a worm or a snake, moisture will power these tiny wriggly robots.

Hygrobots actually inch forward by absorbing humidity from their surrounding environment. Created by researchers at the Seoul National University, South Korea, these tiny robots can twist, wriggle forwards and back, and crawl just as snakes or worms do. The researchers envisage these hygrobots being useful for a variety of applications in the future, which could include delivering drugs within the human body.

According to the researchers, they received the inspiration for hygrobots from observing plants, and they have described their findings in the journal Science Robotics. Using hydroexpansion, plants change their shape and size when they absorb water from the air or ground. For instance, pinecones know when to close and when to open, depending on whether the air is wet or dry, and this helps them to disperse seeds more effectively. Even earlier, plants have provided inspiration for robots—researchers created robots in imitation of algae.

Although hygrobots are not made of plant cellulose, they mimic the mechanism the plants use. As moisture is available almost everywhere, using it as a source of power for operating robots makes sense. Unlike batteries, moisture is non-toxic, and does not have the tendency to explode. This is an important consideration, as microbots, for instance the spermbot, are usually required to operate within the human body.

One can visualize the motion of hygrobots by observing the Pelargonium carnosum seed bristle—a shrub-like plant found in Africa. The hygrobot mimics the motion of the bristles, as it has two layers made of nanofibers. While one layer absorbs moisture, the other does not.

Placing the bot on a wet surface causes the humidity-absorbing layer to swell up, making the bot move up and away from the wet surface. This allows the layer to lose moisture and dry up, and the bot comes back down—the cycle repeating itself—allowing the bot to move. The researchers demonstrated a hygrobot coated with antibodies crawling across a bacteria-filled culture plate. It could sterilize the entire plate without requiring any artificial power source.

This is how the researchers imagine the bots of the future will deliver drugs within the human body, propelling themselves using only the moisture of the skin. Other than responding only to water vapor, researchers say they could equip them with sensors that respond to other gases as well.

However, this is not the first instance of scientists working with tiny robots. Last year, researchers had created a hydrogel bot for biomedical applications that a magnet could activate. It was able to release localized chemo doses for treatment of tumors.

Not only medical, military, and industrial applications will also benefit from light and agile microbots that do not require additional power inputs to operate. Hygrobot, the biologically inspired bilayer structure harnessing energy from the environmental humidity uses ratchets to move forward. The hygroscopically responsive film quickly swells and shrinks lengthwise in response to a change in humidity.

SALTO the Agile Jumping Robot

In the Biomimetic Millisystems Lab at UC Berkeley, Duncan Haldane is responsible for numerous bite-sized bio-inspired robots—robots with hairs, robots with tails, robots with wings, and running robots. Haldane and the other members of the lab look at the most talented and capable animals for inspiration for their robotic designs.

The African Galago or Bushbaby is one such animal. It is a fluffy, cute, talented, and capable little jumping animal weighing only a few kilos. However, this little creature can jump over and clear bushes nearly two meters tall in a single bound. Biologists have discovered that Galagos’ legs are specially structured to amplify the power of their tendons and muscles. Haldane and his team accordingly made Salto, a legged robot weighing only a hundred grams, endowing it with agility and the most impressive jumping skills. Salto features in a paper the new journal Science Robotics.

Jumping is not only about how high one can jump, how frequently you can jump also matters. Haldane and his team have coined the term agility to refer to how far upwards one can go while jumping repeatedly. Technically, they define it as the maximum average vertical velocity achieved while performing repeated jumps. For a Galago, it can jump 1.7 m in height repeatedly every 0.78 s—an agility of 2.2 m/s.

Therefore, to be called agile, the jumper not only has to jump high, he also has to be able to jump frequently. For instance, although EPFL’s Jumper can jump to impressive heights of 1.3 m, it can only do so every four seconds. That means its agility is a measly 0.325 m/s. On the other hand, Minitaur can jump up only to 0.48 m, but it does so every 0.43 s, which gives it a much better agility of 1.1 m/s, despite its lower jumping ability.

That means improving agility involves jumping either higher, or more frequently, or both. Galagos are agile, because of not only their ability to jump high, but also their ability to do so repeatedly. Most jumping robots have low agility, because, they need to spend time winding a spring for storing up enough energy to jump again, and this reduces their jump frequency. The researchers at Berkeley wanted a robot with an agility matching that of the Galagos. With Salto, they have come close, as Salto can jump 1 m every 0.58 seconds, earning an agility of 1.7 m/s.

Just as with many jumping robots, Salto also uses an elastic element, such as a spring, for the starting point. For Salto, the spring, actually a piece of twistable rubber is placed in series between a motor and the environment, making a Series Elastic Actuator (SEA). Apart from protecting the motor, SEAs also allow for force control and power modulation, while allowing the robot to recover some energy passively.

Such springs are available to the Galagos in the form of their tendons and muscles. However, the leg of the Galagos is in such a form that allows it to output nearly 15 times more force than its muscles can by themselves. Haldane has used this same design for Salto as well.

Six-Legged Robot is faster than Insects

Evolution follows very intelligent designs, filtering out the failures by trial and error. However, evolution in nature takes place over billions of years, but that span of time may not be available to designers of robots. Usually, robotics design, inspired by biology, is about the designer figuring out the clever tricks that evolution has perfected and applying them to the robot for beating nature at her own game.

For instance, studies have shown that most six-legged insects move with a tripedal gait, meaning they move at least three legs at a time. On the other hand, EPFL researchers from Lausanne, Switzerland, have reported in Nature Communications that a bipedal gait for a hexapod is more efficient and a faster way of moving—using two active legs at once.

When moving, especially when moving fast, animals with legs tend to minimize the time their legs remain in contact with the ground. Therefore, fast moving mammals prioritize flight phases, in which their motion seems more like a sequence of jumps rather than fast walking. However, for hexapedal insects, whether they are moving slowly or fast, movement consists of keeping at least three legs in contact with the ground at all times.

Mathematically, the tripedal gait is less efficient than a gait involving two legs. This is simple to calculate, as a hexapod using three legs at a time gets two power strokes per gait cycle, whereas, if it used two legs at a time, it would instead get three. The EPFL researchers tested this theory on hexapedal robots. They conclusively proved that by using two legs at once instead of three, hexapedal robots could move 25% faster. Therefore, rather than use the natural tripedal gait of insects, a hexapedal walking robot, with a bipedal gait, could be more dynamic, although statically not so stable. That brought the investigators to an interesting question: why are insects using a slower gait, when they could be moving faster?

The researchers found that insects also needed to move on places that are not always upright and horizontal, such as walls and ceilings. Walking on walls and ceilings requires feet that stick or grab to surfaces—most flying insects have this capability. They concluded that for walking while clinging to surfaces, it is best to follow a tripedal gait, but when running on the ground, a bipedal gait is faster.

The researchers tested their theory further by negating the adhesive property of insects’ feet by giving flies some polymer boots. The flies responded by moving on to a bipedal gait from a tripedal one. Even when placed on a very slippery surface, their behavior did not change, suggesting the tripedal gait was due to the structure causing the adhesion in the legs, or the sensory feedback the legs generated. This experiment proved conclusively that even when adhesion was unnecessary, insects could not move to a bipedal gait, as having sticky feet, they needed the leverage of three legs to unstick the other three.

Such biorobotics helps us in two ways. On one hand, it explains why nature works the way it does, and on the other, it shows how we can make faster and better robots.