Compliant Shape Memory Alloy Gripper, Soft Robot Mechanics and Design
Spring 2014
During spring semester of my junior year, classmate Mike O'Connor and I designed a novel robotic gripper actuated using shape memory alloys.
Shape memory alloys (SMAs) are adaptable, flexible, and lightweight compared to conventional modes of actuation. However, SMA’s are still a maturing technology and all of their practical applications have not yet been realized. This work explores the potential for SMA actuation of bending actuators to create a gripping device. Through intensive prototyping, we determined to use a coil expansion spring SMA integrated in silicone molded arms. The final gripper proved capable of lifting geometrically diverse small household objects. In addition, the device was used to validate the theoretically modeled gripping forces. This work shows that SMAs have the potential to replace conventional actuation methods in low force applications. Feel free to check out our full report here.
My work for this project included:
- Studied shape memory alloy properties and applications
- Conceptualized and prototyped shape memory alloy bending actuators
- Molded silicon arms embedded with fishing thread designed to curl under tension
- Designed configurable gripper shell to shape memory alloy performance
- Successfully tested gripper on a variety of household objects
- Used Mathematica to generate analytical performance model and compared predictions to results
