## 3 Results
### Blood Cell lysis Using the ICP Phenomena  
We initially explored how ICP occurs in our device. As previously indicated, an electric field with a sufficient strength and duration must be applied to disrupt the blood cell membrane. Therefore, we aimed to determine the strength of the electric field required for lysis before the blood cells are injected into the device by observing the effect of the ion depletion region on the behavior of particles flowing from the inlet. Generally, it is difficult to directly observe the ICP phenomena because it involves ion movement. However, charged particles are pushed out of the ion depletion region and are concentrated on the anodic side of the ion depletion region. We observed ICP generation using fluorescein sodium salt, a green fluorescent molecule widely used in microfluidics. Figure 2 shows the effect of the electric field and ICP phenomena on particle behavior. The test solution was prepared by adding fluorescein sodium salt to 1X phosphate-buffered saline (PBS) such that the salt concentration of the test solution was similar to that of blood. Figure 2a,b show the behavior of the particles when an electric field was directly applied to the microchannel without passing through the Nafion membrane, whereas Figure 2c and d show the behavior of the particles when ICP was applied through the Nafion membrane. The behavior of the fluorescent particles when no electric field was applied is shown in Figure 2a,c. After the test solution was sufficiently filled, the particles passing through the Nafion membrane were not subjected to any force other than the drag force, and they flowed to the outlet. Therefore, the fluorescence concentration inside the microchannel remained constant throughout the entire section. Figure 2b shows that even when a voltage of 75 V was directly applied to the microchannel, the particles exhibited almost no change in movement compared with the results shown in Figure 2a, where no electric field was applied. Generally, when an electric field is applied, the flow changes due to the electroosmosis phenomenon. Here, a sufficiently strong pressure-driven flow was applied in the developed device, thus confirming that there was no significant change in the flow and particle behavior. Figure 2d shows the results when the voltage of 75 V at the inlet electrode was applied through the Nafion membrane to the ground buffer channel. We observed that the ICP phenomenon created an ion depletion region near the Nafion membrane, and the charged fluorescent particles were attracted to the anode (left side of the image). Because the applied electric field was sufficiently strong and the ion depletion region covered the entire microchannel area around the Nafion membrane, the fluorescent particles could not pass through the ion depletion region. Consequently, they were concentrated in front of the Nafion membrane, as indicated by the bright green fluorescence in Figure 2d. In addition, a dark area was observed at the outlet of the Nafion membrane. As the non-polarized water molecules continued to flow to the outlet, all the fluorescent particles behind the Nafion membrane were swept away, and the outlet direction appeared dark. Furthermore, we quantitatively analyzed the particle concentration due to the ICP phenomenon through fluorescence intensity analysis. Figure 2e shows a graphical representation of the intensity of green fluorescence against the direction of fluid flow in the microchannel. The graph shows that there is almost no variation in fluorescence intensity with the direction of fluid flow, except for the ICP_75 V case, where a voltage of 75 V was applied through the Nafion membrane. The intensity of the fluorescent particles, represented by the green line, shows a strong fluorescence intensity at the beginning of the microchannel image. As shown in Figure 2d, where the particles are concentrated in front of the Nafion membrane, the intensity decreases with distance.