Metal Nanoshells are precisely layered metal-dielectric nanoparticles whose optical resonances are controlled
by the relative thicknesses of their constituent layers. This layered topology gives precise control over
optical fields at subwavelength dimensions, and can be considered a fundamental component of nano-optics,
where electromagnetic properties are controlled by nanoscale design. This topology also provides a new way
to study the electronic and dynamical properties of mesoscopic metals that is complementary to the
low-temperature, transport based methods commonly used.
Unlike photonic crystals, which require long-range periodicity to manipulate light, individual Metal Nanoshells can be integrated with existing materials and device structures, allowing one to modify and manipulate the optical properties of materials in unique and unusual ways. The example of a nanoshell-polymer composite material with a dramatic opto-mechanical response will be discussed. Gold nanoshells also provide a biocompatible substrate for the conjugation of proteins: this has led to the development of real time medical testing based on Surface Enhanced Raman Scattering, and also provides a promising strategy for cell-specific photothermal cancer therapy.