Next, the SU-8 3025 microstructures were added to the SU-8 3010 silicon wafer. SU-8 3025 photoresist was spin-coated on the wafer at 4500 rpm for 30 seconds. The coated wafer was soft baked at 65 °C for 1 minute, 95 °C for 4.5 minutes, and then 65 °C for 1 minute. The designed mask for the SU-8 3025 pattern was then aligned with the SU-8 3010 pattern and exposed for 55 seconds. After waiting for approximately 30 minutes, the wafer was developed using SU-8 developer (MicroChem). The finished structure was measured to be 18–20 µm in thickness.