Fig. 1: Illustration of contact lens sensor.

a 3D structural model and the layered schematic view of the contact lens sensor. b Data acquisition scheme of IOP monitoring. c Cross-sectional SEM of the microchannels, scale bar: 100 μm. d Photograph of contact lens sensor, scale bar: 3 mm. Figure 1a, b were created by author Hongbin An using the SoliderWorks and 3D Max software, respectively. The figures were created to describe the structure of the contact lens sensor, as well as the components and principles of LC IOP measurement system, respectively. Figure 1c was created by author Hongbin An using a scanning electron microscope (Helios NanoLab G3 CX, FEI company, America). The photograph was created to show how the contact lens sensor was manufactured. A channel cross-section containing liquid metal was not used because the liquid fluidity would have resulted in a dirty cutout, which was unsightly, interfered with observation, and did not visually represent our ideas. While, the green line in the photograph represents the scale bar as 100 μm. Figure 1d was created by author Xian Wang using a smartphone (OnePlus Ace 2 Pro, OPPO Guangdong Mobile Communications Co., Ltd, China). While, the white line in the photograph represents the scale bar as 3 mm.