Colloquia

Summary

Voice coil actuators, known for their frictionless, precise movements within compact designs, are widely used in applications demanding high accuracy and responsiveness. However, a key limitation of voice coil actuators is the generation of heat within the copper coil, which dissipates to the surrounding. The heat dissipation from the coil to its surroundings is a critical factor, particularly astronomy applications which require highly stable temperatures. This research presents a new type of miniature actuator, designed for precise movement, using a flexure and utilizing a superconducting solenoid coil. This innovative design allows for high force generation with minimal heat production, making it suitable for applications requiring a highly stable environment. The actuator's key component is a spiral flexure mechanism, optimized for high stiffness over the movement range. Several flexure concepts are considered and optimised for high support stiffness. A deeper analysis into the spiral flexure has been done through analytical approximations, FEM analysis and experiments. The spiral flexure shows consistent results that makes it a cheap alternative for precise motion. A compact demonstrator, demonstrates high force output and minimal heat dissipation at liquid nitrogen temperatures. The actuator's motion and stiffness closely match theoretical predictions and simulations, making it a reliable and predictable tool for various applications.