An Adaptive Soft Plasmonic Nanosheet Resonator

Current micro/nanomechanical system are usually based on rigid crystalline semiconductors that normally have high quality factors but lack adaptive responses to variable frequencies—a capability ubiquitous for communications in the biological world, such as bat and whale calls. Here, a soft mechanical resonator based on a freestanding organic–inorganic hybrid plasmonic superlattice nanosheet is demonstrated, which can respond adaptively to either incident light intensity or wavelength. This is achieved because of strong plasmonic coupling in closely packed nanocrystals which can efficiently concentrate and convert photons into heat. The heat causes the polymer matrix to expand, leading to a change in the nanomechanical properties of the plasmonic nanosheet. Notably, the adaptive frequency responses are also reversible and the responsive ranges are fine-tunable by adjusting the constituent nanocrystal building blocks. It is believed that the plasmonic nanosheets may open a new route to design next-generation intelligent bio-mimicking opto-mechanical resonance systems.