A report proposes the use of muscle wires as mechanical actuators for planetary-exploration robots. Muscle wires are commercially available in kit form in the hobby market, and have been described (though not explicitly called "muscle wires") in previous articles in NASA Tech Briefs. A muscle wire is made of a shape-memory alloy. By sending a sufficient electric current along the wire, one can heat the wire above its transition temperature, causing it to change length. When the current is turned off, the wire cools, returning to its original length. The aspects of muscle wires that make them attractive for planetary-exploration robots are low mass, simplicity, and the ability to exert large tensile forces (thousands of times their own weights); in these aspects, muscle wires are superior to conventional electric motors. Moreover, because of their low thermal masses, muscle wires would respond to turn-on and turn-off of currents rapidly enough for the actuation frequencies needed in planetary-exploration robots.
This work was done by Kumar Ramohalli of Caltech for NASA's Jet Propulsion Laboratory. To obtain a copy of the report, "Muscle Wires for Efficient Planetary Exploration Robots," access the Technical Support Package (TSP) free on-line at www.techbriefs.com under the Materials category, or circle no. 111 on the TSP Order Card in this issue to receive a copy by mail ($5 charge). NPO-20194
This Brief includes a Technical Support Package (TSP).
Muscle wires for planetary-exploration robots
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Overview
The document discusses the development and application of muscle wires, specifically shape-memory alloys, for use in planetary-exploration robots. These innovative actuators are highlighted for their lightweight, simplicity, and ability to generate significant forces, making them advantageous over traditional electric motors. The research is conducted by NASA's Jet Propulsion Laboratory (JPL) and is part of a broader initiative to enhance robotic capabilities for space exploration.
Muscle wires operate by changing shape in response to electrical stimulation, allowing them to mimic the contraction and relaxation of biological muscles. This property enables robots to perform complex movements and tasks in challenging environments, such as those found on other planets or asteroids. The document emphasizes the potential of these wires to improve the dexterity and functionality of robotic systems, which is crucial for tasks like sample collection, navigation, and manipulation of objects in extraterrestrial settings.
The technical specifications of the muscle wires are discussed, including their torque and power requirements. For instance, the document mentions a torque of 32.7E-3 N-m and a power draw of approximately 400 Watts when the robotic arm is in operation. These parameters are essential for understanding the performance capabilities of the muscle wires in practical applications.
Additionally, the document outlines the collaborative efforts of various researchers and institutions, including the support from NASA, to advance the technology and explore its potential applications in space missions. The research aims to address the challenges of operating robots in remote and harsh environments, where traditional systems may struggle.
Overall, the document serves as a technical support package that provides insights into the innovative use of muscle wires in robotic systems designed for planetary exploration. It highlights the importance of this technology in enhancing the efficiency and effectiveness of robotic missions, ultimately contributing to our understanding of other celestial bodies and the potential for future exploration. The work is positioned as a significant step forward in the field of robotics and space exploration, showcasing NASA's commitment to advancing technology for scientific discovery.
