Liquid‐Metal‐Enabled Flexible Metasurface with Self‐Healing Characteristics

Abstract A flexible self‐healing metasurface using gallium‐based liquid metal encapsulated in polydimethylsiloxane (PDMS) operating in the X‐band (8–12 GHz) is reported. A band‐stop metasurface with center frequency at 9.82 GHz is designed using floating patches surrounding the respective end cap of a Jerusalem cross. A large‐scale (up to 10 × 10 array) metasurface is patterned in PDMS and a rapid manufacturing method of vacuum filling using ultra‐low pressure is used to yield parallel encapsulation of liquid metal in PDMS. The fabricated metasurface is physically flexible and its flexibility is repeatedly tested for bendability, stretchability (up to ≈89.13%), twistability, and foldability. Transmission characteristics of the flexible metasurface are measured in waveguide and free‐space environments and it is found that the band‐stop center frequency agrees well with the design. The flexible metasurface also is tested for its repairability and self‐healing characteristics. The metasurface is partially or fully cut at certain part and the partial/full cut part of the metasurface is repaired by applying external pressure or using Kapton tape/UV glue. Those repaired metasurfaces show restoration of original transmission characteristics with minimal shift in frequency and magnitude.