Italian researchers designed and manufactured an artificial pneumatic muscle composed of a 3D printed structure, which can stretch and contract as needed. According to the report of science robot magazine, this is a pneumatic hand made in a single printing process and composed of 18 different Grace (actuators that can shrink and elongate). The creation of artificial muscles is one of the goals pursued in the field of robotics, because in nature, muscle tissues have complex characteristics, from rapid and powerful contraction to small and precise changes in shape, which can be flexibly controlled and can also perform highly flexible movements. A single muscle fiber can only achieve contraction. However, it is their specific arrangement in the complex muscle structure that can achieve joint deformation such as bending, torsion and anti motion. The research team started from a single pneumatic actuator to try to make a breakthrough. Each actuator can be expanded, extended and contracted simply by its geometry, similar to the spindle with pleats, including an independent unit that can be 3D printed and manufactured using different materials and sizes. Various grace prints and assembles into complex architectures to provide the required types of motion. According to the researchers, these grace can be made into different sizes, which can change their performance in deformation and strength. They can also be manufactured with various materials and technologies, and even built into the structure to be manufactured. The researchers used a commercial 3D printer to produce a pneumatic hand through a printing process, and demonstrated the characteristics of grace. The material used for printing the pneumatic hand is a soft resin, which contains 18 grace of different sizes and shapes. Therefore, it can bend fingers, twist palms and rotate wrists with a pressure of only a few tenths of a PA. The pneumatic hand weighs about 100g and is about the size of a human hand. The new design enables the pneumatic hand to support more than 1000 times its own weight, depending on the material used to make them. In fact, the generated force and the required pressure can be increased or decreased by using materials of different stiffness and modifying the thickness of the films constituting these actuators, while maintaining the same contraction and extension properties. The core of this achievement is grace. This kind of actuator can not only shrink and stretch, but also be realized with different materials and mechanical properties in different sizes and scales, so as to complete an unprecedented wide and realistic movement. Through the effective combination of grace, scientists may 3D print out sufficiently powerful and flexible "software actuators" in the future, with applications ranging from biodiversity protection to daily care of the elderly, so that this artificial device can truly integrate with the natural and social environment. (news agency)