Rapid Electro‐Thermal Micro‐Actuation of Flat Optics Enabled by Laser‐Induced Graphene on Colorless Polyimide Substrates

Abstract A high‐performance electro‐thermal micro‐actuator for active optical devices is demonstrated, fabricated via the direct laser writing (DLW) of laser‐induced graphene (LIG) onto a colorless polyimide (CPI) substrate. This approach leverages the unique combination of LIG's exceptional thermal conductivity (4.70–11.3 W m⁻¹K⁻¹, representing a two‐order‐of‐magnitude enhancement over CPI) and CPI's inherent transparency, flexibility, and high thermal stability. The LIG exhibits rapid thermal actuation of optically reflective surface with frequencies up to 2 kHz. Furthermore, the optically diffractive electro‐thermal actuators enable 0.5‐millidegree‐resolution beam steering with 0.9 s response times, transitioning the LIG actuators from the quasi‐steady state to an active regime. This high‐speed, high‐precision actuation mechanism demonstrates the potential for high‐speed dynamic optical control in compact systems, such as focus‐tunable lenses and beam‐steering devices. The single‐step DLW fabrication process on a readily available, flexible, and transparent substrate offers significant advantages in terms of cost‐effectiveness and scalability, making this approach highly promising for next‐generation lightweight, flexible, and integrated optoelectronic devices.