Real-Time Visual Sensing of Heat or Mass Transfer Processes for Microfluids via Tamm Plasmon Polaritons.

Heat or mass transfer processes of microfluids are very important in bioscience, environmental engineering, and food science, which are still hard to detect in real time. To overcome this difficulty, we try to use Tamm plasmon polaritons to enhance the interaction of light with microfluids. The main structure of the proposed configuration is Ag-photonic crystal (PhC) cavity, which can generate strong photonic localization by exciting Tamm plasmon polaritons. The results show that the enhancement of light intensity reaches ∼90 times in the cavity and the reflectance spectrum of the proposed structure exists in a narrow valley near 632.8 nm. This illustrates the generation of Tamm plasmon polaritons in the proposed structure. By injecting the microfluids into the cavity, the heat and mass transfer processes of the microfluids will have considerable influence on the reflectance of the proposed structure. Simulation results show that the concentration or temperature distributions of the microfluids can be effectively detected by analyzing the brightness of the imaging pictures, which is real-time and visible. Meanwhile, the sensitivity of the proposed configuration can be tuned by setting proper base parameters. This proposed configuration will have great potential in the study of microfluids, especially for the dynamic processes.