AbstractThe Casimir‐Lifshitz force, F_{C − L}, has become a subject of great interest to both theoretical and applied physics communities due to its fundamental properties and potential technological implications in emerging nano‐scale devices. Recent cutting‐edge experiments have demonstrated the potential of quantum trapping at the nano‐scale assisted by F_{C − L} in metallic planar plates immersed in fluids through appropriate stratification of the inner dielectric media, opening up new avenues for exploring physics at the nano‐scale. This review article provides an overview of the latest results in Casimir‐Lifshitz based‐optical resonator schemes and their potential applications in fields such as microfluidic devices, bio‐nano and micro electromechanical systems (NEMS and MEMS), strong coupling, polaritonic chemistry, photo‐chemistry, sensing, and metrology. The use of these optical resonators provides a versatile platform for fundamental studies and technological applications at the nano‐scale, with the potential to revolutionize various fields and create new opportunities for research.