In recent years, roboticists have developed increasingly complex robotic systems designed to mimic both the structure and function of the human body. This work involves robotic arms, which are grippers that allow robots to grasp and manipulate objects the same way humans do in everyday tasks.

Ideally, robotic arms should be able to make very precise movements, be relatively cost-effective, and easy to manufacture. However, most of the skeletal designs for robotic arms presented so far have a very complex design with a large number of advanced components, making them difficult to produce on a large scale.

Researchers at the Massachusetts Institute of Technology (MIT) recently created a new, high-precision robotic arm that can be scaled up more easily because its components can be created using common technologies such as 3D printing and laser cutting. Robotic arm featured in an article published in the journal 2023 IEEE International Conference on Soft Robotics (RoboSoft)It is based on what is known as modular construction; This means that it consists of various building blocks that can be rearranged to achieve different movements.

“Although parallel grippers and multi-fingered robotic hands have been widely developed and used in structured environments, designing a highly articulated robotic hand comparable to human hands for a variety of daily manipulation and grasping tasks still remains a challenge in robotics,” Chao Liu said. Andrea Moncada and colleagues wrote in their paper.

“Agility generally requires more actuators, but also results in a more complex mechanism design and is more expensive to manufacture and maintain. Soft materials can provide compliance and safety in interaction with the physical world, but are difficult to model.”

The main goal of Liu, Moncada and their collaborators’ recent work was to create a flexible robotic arm that does not require particularly complex and expensive components. However, this flexible arm needs to be able to perform more advanced movements than robotic grippers based solely on solid materials and, as a result, improve object gripping abilities.

“This work represents a biotechnology-inspired hybrid robotic arm that combines soft materials and hard elements,” Liu, Moncada and colleagues wrote. “The sensors are integrated into rigid bodies, providing a simple way to assess posture with high precision.”

A modular robotic arm created by a team of researchers at MIT can be easily adapted to best suit different applications. For example, researchers can add or remove fingers and reposition their components to achieve different types of grip or improve performance in certain scenarios.

“The proposed arm has a modular structure that allows rapid fabrication and programming,” the researchers write. “The manufacturing process was carefully designed so that the entire pen could be made from inexpensive materials and assembled efficiently.”

It is noteworthy that both hard and soft components used to create the new robot arm are easy to manufacture. The “bones” that make up the skeleton of the arm can be printed in 3D, and the magnets, sensors and cables inside are easily available on the market.

The team used a simple two-step molding process to create a skin that surrounds the bones. They first created various parts of the mold using 3D printing and then used these parts to mold the silicone into the finger shape.

As part of their research, Liu, Monad and their colleagues created a prototype of their five-fingered hand and evaluated its performance. They found that the hand can successfully perform different types of grasping, mimicking the way the human hand grasps and holds different objects. Its robotic arms are capable of firmly grasping flexible and rigid objects of various sizes, including plastic cups, pencils and round plastic rings.

The robotic arm may soon be developed and tested to improve and test its capabilities. It could eventually be integrated with other robotic limbs to create scalable humanoid robots that better manipulate objects.

“Future work includes palm design with additional rotation angle for the thumb, compact wrist design for holding electronic devices, and developing a control strategy for dexterous manipulation and grasping,” the researchers conclude in their paper. Source