Fig. 1. Diagram of production process. (a) Pouring; (b) spin coating; (c) exposure; (d) development; (e) etching; (f) removing glue

Fig. 2. Morphologies of photoresist after different development time. (a) 25 s; (b) 30 s; (c) 35 s

Fig. 3. Electrode morphologies after different etching time. (a) 180 s; (b) 210 s; (c) 240 s

Fig. 4. Comparison of photoresist morphologies with different sizes after development. (a) 200 μm; (b) 100 μm; (c) 50 μm; (d) 20 μm; (e) 10 μm; (f) 2 μm

Fig. 5. Comparison of electrode effects with different size after glue removal. (a) 200 μm; (b) 100 μm; (c) 50 μm; (d) 20 μm; (e) 10 μm; (f) 2 μm

Fig. 6. 2 μm electrode morphology under atomic force microscope

Fig. 7. Cross-sectional shape curves of 2 μm electrode and glass substrate under atomic force microscope