Cell-Based Biohybrid Sensor Device for Chemical Source Direction Estimation
(a) Relationship between the assigned angle corresponding to each region of interest (ROI) and the time to peak intensity () at each ROI. The curves were fitted by sinusoidal approximation to the plots. The actual experimental data are indicated by the dots, and the fitting is indicated as the curves. The colors orange, green, and blue represent the data relating to chemical-source-direction angles of 45°, 90°, and 135°, respectively. (b) Fluorescence images of the cell-based biohybrid sensor 210 s after applying muscarine using the device for chemical-solution flow. White arrows indicate the direction of the applied chemical, whereas the colored arrows indicate the estimated direction. These colors correspond to the counterpart ones used in (a). Scale bar: 500 μm.