Mechanically actuated frequency reconfigurable metamaterial absorber

[Display omitted] •A mechanically actuated frequency reconfigurable metamaterial electromagnetic absorber is proposed.•A linear actuator and microcontroller is used for changing air substrate thickness mechanically.•The absorption frequency changes from 6.96 GHz to 5.78 GHz when the air substrate thickness is changed from 17 mm to 26 mm.•A rate of change for the absorption frequency relative to the air substrate thickness is 0.12 (GHz/mm).•The proposed metamaterial absorber can be potentially used for wireless pressure sensor applications. In this paper, a mechanically actuated frequency reconfigurable metamaterial electromagnetic absorber is proposed. The absorber’s metamaterial unit cell is designed to exploit LC resonance from inductive and capacitive coupling. Because this inductance and capacitance determine the absorber’s resonant frequency, we propose a mechanical tuning method that changes the resonant frequency by changing the overall thickness of the metamaterial unit cell. The proposed unit cell consists of an FR4 dielectric substrate with fixed thickness and an air substrate with tunable thickness. When the air substrate thickness is varied over the range of 17 mm to 26 mm, the absorber’s resonant frequency changes from 6.96 GHz to 5.79 GHz in EM simulation. In order to verify the proposed idea, a metamaterial absorber was fabricated as a 17 × 17 array of unit cells and a linear actuator was used to control the thickness of the air substrate. We experimentally demonstrated that the absorption frequency changes from 6.96 GHz to 5.78 GHz with 0.12 (GHz/mm) sensitivity when the air substrate thickness is mechanically changed from 17 mm to 26 mm.