# Implementation of Atomically Thick Graphene and Its Derivatives in Electromagnetic Absorbers
## 4 Conclusions and Outlook  
In summary, this work introduces the implementation of graphene and its derivatives in quarter-wavelength and metasurface absorbers for EM wave absorption. The experimental results on narrowband graphene Salisbury screen with electrically tunable absorption strength have been discussed. In addition, graphene or reduced graphene oxide can also be combined with other magnetic or non-magnetic materials for broadband Dallenbach absorber design. The high permeability and/or permittivity of the synthesized composites can help to keep the thickness of resulting microwave Dallenbach absorbers within a few millimeters. However, since most of the theoretical investigations of graphene Dallenbach absorbers are based on the measured complex permeability and/or permittivity, further experimental investigations are requested to validate the theoretical results and the effects of incident angles are also to be explored. In addition, while the theoretical explorations on graphene metasurface absorber demonstrate promising reconfigurability, a limited number of experimental investigations only demonstrate mechanically rather than electrically tunable absorption performance due to the limitation of immature fabrication processes. The future research directions of graphene metasurface absorbers include the developments of new design technologies to relax the requirements of device fabrication and new manufacturing technologies to reduce the device cost. The former direction tends to reduce the possibility of device failure caused by the immature fabrication process and the latter direction aims to make graphene metasurface absorbers financially viable for industrial  
Figure 12: (**a**) image of the fabricated Type-A sample and measurement setup; (**b**) measured and simulated absorption spectra of Type-A metasurface with various graphene sheet resistances; (**c**) schematic of Type-B sample; (**d**) measured and simulated absorption spectra of Type-B metasurface with various graphene sheet resistances, reprinted with permission from Ref. [134].  
and military applications. Moreover, graphene may also be combined with other tunable materials such as liquid crystal to realize reconfigurable multi-functional metasurfaces. With the development of graphene synthesis and device fabrication technologies, the graphene metasurface absorbers with reconfigurable absorption performance may play an important role in the development of smart EM wave absorbing materials.  
[PERSON] participated in resource harvesting as well as writing, editing and reviewing of the whole article. [PERSON] participated in the writing and reviewing of Section 3. [PERSON] and [PERSON] participated in resource harvesting and the writing of Sections 1 and 2. [PERSON] and [PERSON] participated in the resource harvesting and writing of Sections 2 and 3.  
This work is financially supported by the Science and Technology Committee of the Central Military Commission of China on the project \"Design and Implementation of Controllable Artificial Electromagnetic Material\".  
The authors would like to thank [PERSON] from Queen Mary University of London for his continuous support and constructive suggestions.  
The authors declare no conflict of interest.