Electrically Reconfigurable Terahertz Metasurface Composed of a Liquid Crystal Elastomer Unit-Cell Array

Reconfigurable terahertz metasurfaces are crucial for next-generation wireless communication, optical computing, and terahertz imaging. However, most planar active metasurfaces are limited by the 2D design freedom and suffer from the ohmic losses induced by the conductivity alteration in the active materials. Here, to our best knowledge, we first present a terahertz soft-MEMS platform composed of electrically driven unit-cell arrayed liquid crystal elastomer (LCE) meta-atoms with plasmon-induced transparency (PIT) pattern, in which each meta-atom can realize reversible 3D mechanical bending. The thermal effect of applied current actuates the individual LCE meta-atom, and the progressive bending of meta-atoms and corresponding PIT spectra modulation up to 26.13% were experimentally observed. Notably, through a 10-fold "heating-recovery" measurement, the high repeatability and stability of LCE meta-atoms are demonstrated, which represents a distinct advantage among reported terahertz MEMS metasurfaces. This platform is compatible with a wide variety of meta-atom architectures and does not require direct physical connection between the meta-atoms and the driving circuit, thus offering a novel approach for the investigation of intelligent, reconfigurable metasurfaces with diverse functionalities, which holds significant promise in next-generation wireless communication and advanced terahertz imaging technologies, as key components to realize smart beam steering, reconfigurable optical mask, and spatial light modulation.