A Fully 3D Printed, Multi-Material, and High Operating Temperature Electromagnetic Actuator

Three-dimensional (3D) printing concepts that combine electrically conductive and electrically insulating materials opens up new opportunities for the design and manufacturing of electromagnetic actuators. While significant research has been conducted to 3D print antennas and planar circuits using silver nanoparticle inks, little focus has been given towards high power (>1 W) actuator applications. In this work, we design a novel 3D printed, centimeter-scale, multi-layer electromagnetic actuator consisting of syringe deposited silver nanoparticle ink on layers of copper-particle-filled polylactic acid (PLA) polymer filament. The Cu-PLA material is not only electrically insulating at moderately high temperatures but is also higher density and more thermally conductive than traditional polymer filaments. These features enable higher operating temperatures, higher burst forces, and longer sustained output. To demonstrate this concept, we first outline the design, material selection, and 3D printing process for a 16-layer, single trace electromagnetic coil. Then, models for the thermal characteristics, force distribution, and mechanical response are developed and compared with experimental results. Measurements show that the electromagnetic coil can produce up to 46 mN of force over 4 mm of stroke with 6.3 W of input power, and can operate indefinitely with 4.2 W of input power at 140^◦C without external cooling. Several applications are demonstrated including a small compliant joint gripper and a speaker. Finally, a fully-integrated, multi-material, single-print actuator and gripper combination is demonstrated to illustrate how this work can be used to create fully-operational single-print mechatronic and robotic systems.