3D printing of functional metallic microstructures and its implementation in electrothermal actuators

Laser-induced forward transfer (LIFT), a 3D additive manufacturing technique is implemented to fabricate a fully metallic functional micro device. Digital deposition of both structural and sacrificial metal constituents in the same setup arrangement is achieved. The final free-standing structure is released by selective chemical wet etching of the support material. Using this approach, a chevron-type electro thermal micro-actuator made of gold was successfully fabricated and its functionality was shown in experiment. Comparison of the measured responses with the model predictions indicates that the thermal conductivity of printed Au is approximately 8 times lower than the bulk value. It is a first demonstration of a functional micron scale actuator printed using LIFT.