Lightweight grippers for robots – why is carbon fiber a good choice?

The term “gripper” is used by manufacturers to describe the part of a robot arm which grabs items and moves them from one place to another. Grippers are used across various industries, including packing goods, woodwork, construction, and automotive assembly. Grippers can come in several types, the most popular being:

  • Human-hand grippers: these grippers may have multiple prongs extending forward to resemble a human hand.
  • Suction grippers: these grippers have high powered suction cups which attach to items in order to transport them.

Crucial Factors To Consider in Gripper Manufacturing

Regardless of what the gripper looks like, robot grippers have one thing in common – they have to be lightweight and incredibly sturdy. 

If a gripper is made of heavier material such as steel, it can result in the robot arm getting weighed down. The arm may start to slow in its performance overtime, which can delay the entire assembly process. The heavy gripper may also overload the arm, so it will not be able to grab heavier items like it is supposed to. It is important to seek out lightweight yet sturdy items when it comes to manufacturing grippers for robots. 

Aluminum grippers may seem like a good option, as they are three times lighter than steel. Aluminum is a relatively soft metal, so it is easier to machine into the gripper shape through computerized machining. However, the progress of technology has provided us with even better, sturdier, and lighter materials than aluminum. These materials include carbon fiber and carbon fiber composites. 

What Is Carbon Fiber?

Carbon fiber has been a popular choice in various industries for decades now, mainly due to its lighter weight and incredible strength. Some of the biggest users of carbon fiber include automotive, aerospace, and medical industries. 

Carbon Fiber, sometimes known as graphite fiber, is a polymer that is very strong yet also very lightweight. Carbon fiber sheets are made of thousands of fibers made of carbon atoms. The fibers are twisted together to make a thick sheet. The fibers are essentially woven together. The weaving style of carbon fiber results in different finishes and slightly different properties in the end result.  For example, a twill weave forms a fabric that is pliable, yet still maintains good stability. 

The process of making carbon fiber results in a strong, lightweight, and durable material that can have a wide variety of uses. Carbon fiber is 5 times stronger than steel, and twice as stiff. However, carbon fiber has a very low weight to strength ratio. This means that carbon fiber panels are extremely lightweight, but also very high in tensile strength. Carbon fiber is used to make anything ranging from sports items, medical equipment, car parts, and robot parts.

Usually, carbon fiber is used in conjunction with other materials, and the end product is called Carbon Fiber Reinforced Polymer (CFRP). The most common materials used to reinforce carbon fiber are thermostats resins such as epoxy. The type of material added to reinforce the carbon fiber affects the properties of the final product. 

Why Carbon Fiber Is Superior For Use Robot Gripper Manufacturing

Advanced automation will often require personalized or customizable solutions. 

Alumunium may seem like the go-to material for robot grippers, but the softness of the metal makes it less durable in the long term. In addition to this, there are even lighter options available. Carbon fiber composites are said to be 42% lighter than aluminum, and it weighs 3 times less than steel. This makes it the superior option over both of these materials.

The properties of carbon fiber that make it suitable for use in robot carbon fiber grippers are as follows:

  1. High tensile strength: Tensile strength refers to how resistant a material is to stretching and pulling. Carbon fiber parts are highly resistant to this kind of damage, which is why it’s such a popular choice in automotive engineering.
  2. Resistance to corrosion: Over the long term, factory environments may lead to corrosion of materials used to make robot grippers. Carbon fiber composites are resistant to oxidation. It is chemically stable and will not rust.
  3. Variety of forms and finishes: Carbon fiber is a woven material, meaning that the fibers are interlocked in various patterns. Different weaving methods result in slightly different end products, so the robot gripper can be customized in a variety of ways to best suit its task and environment. 
  4. Lightweight: The biggest advantage that carbon fiber holds over its rivals is its weight. The strength to weight ratio of carbon fiber is very favorable. You can get a robot gripper which is virtually indestructible, and doesn’t weigh down the arm either.
  5. Low Thermal Expansion: Carbon fiber is very resistant to temperature related changes. This means that the carbon fiber gripper will not expand or contract when exposed to differing temperatures. It is ideal for factory or assembly line placement for this reason.

Overall, the benefits of carbon fiber robot grippers include:

  • 42% weight reduction
  • 30% stiffness improvement
  • Greater loading capacity of arm
  • Higher operation speed of arm
  • Increased durability/ longer life of robot arm
  • Sleek, high tech matte black appearance

How are carbon fiber grippers made?

Carbon fiber grippers can be added to an existing robot in order to reduce weight and increase its effectiveness. Following an analysis of the robot and its existing parts, CNC machined carbon fiber plates need to be commissioned from a manufacturer of carbon fiber plates. These plates can be customized, so consultation with the company is necessary before an order is placed. The customized carbon fiber grippers can then be used in place of the previous grippers, and a weight reduction comparison should be recorded. 

Conclusion

Overall, carbon fiber poses significant competition for traditional materials such as aluminum and steel when it comes to manufacturing grippers for robot arms. The high strength to weight ratio of carbon fiber composites, as well as its tolerance for different temperatures and its durability, have made it the best possible choice for robot arms. Customized Carbon fiber sheets of varying thicknesses can be manufactured for the purpose of creating a more effective robot arm. The end result should make the robot’s performance faster and more effective, and it will also be more resistant to damage in the long term.

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