###### Abstract  
Blood is a widely used sample for diagnosing diseases such as malaria and diabetes. While diagnostic techniques have advanced, sample preparation remains labor-intensive, requiring steps like mixing and centrifugation. Microfluidic technologies have automated parts of this process, including cell lysis, yet challenges persist. Electrical lysis offers a chemical-free, continuous approach, but lysing small cells like red blood cells requires high electric fields, which can damage electrodes and cause system failures. Here, we present a microfluidic device utilizing ion concentration polarization (ICP) for rapid blood cell lysis at 75 V. Fluorescence imaging confirmed the formation of an ion depletion region near the Nafion(r) nanochannel membrane, where the electric field was concentrated across the entire microchannel width. This phenomenon enabled the efficient trapping and lysis of blood cells under these conditions. Continuous blood injection achieved a lysis time of 0.3 s with an efficiency exceeding 99.4%. Moreover, lysed cell contents accumulated near the Nafion membrane, forming a concentrated lysate. This approach eliminates the need for high-voltage circuits or chemical reagents, offering a simple yet effective method for blood cell lysis. The proposed device is expected to advance lab-on-a-chip and point-of-care diagnostics by enabling rapid and continuous sample processing. hemolysis; analysis of blood cell components; bio sample analysis; microfluidic devices; ion concentration polarization 20 potential for improvement [6; 7]. Conventional approaches typically require trained laboratory personnel to perform multiple manual tasks, such as pipetting, centrifugation, and solution exchange. These procedures introduce variability and often extend the total preparation time to 30 to 60 min per assay. In addition, conventional workflows depend on bulky benchtop equipment, including centrifuges and biosafety cabinets. These instruments occupy substantial laboratory space and limit the portability of the system [8; 9; 10]. Recent advances in microfluidics have enabled the automation of these labor-intensive and skill-dependent tasks on microchips [11; 12; 13]. Microfluidic technologies have been developed for pre-treatment processes such as solution injection [14], mixing [15], cell lysis [16; 17], and sample concentration [18]. These advances have facilitated the emergence of point-of-care diagnostic systems. Of these processes, cell lysis is a critical step in cell analysis and has been extensively studied using mechanical [19], chemical [20; 21], and thermal [22; 23] methods. Among these, chemical reagents are most commonly used to dissolve cell membranes owing to their ability to continuously lyse cells without accumulating debris or causing thermal damage, which are significant drawbacks of mechanical and thermal methods. Consequently, many researchers have adopted microfluidic chemical lysis methods for sample preparation [24; 25]. However, chemical cell lysis methods can denature intracellular substances such as proteins, posing a significant limitation as a pre-treatment technique [26; 27; 28]. Researchers have attempted to mitigate this issue by modifying the composition of chemical reagents; however, these methods remain nonideal. The technologies that leveraged electric fields to disrupt cells emerged in the early 2000s. Applying an electric field with a potential of approximately 1.5 V to a cell membrane can irreversibly puncture it. Directly applying an electric field of several hundred kilovolts to a microchip can lyse cells ranging in size from tens to hundreds of micrometers. Electrical cell lysis has been proposed as an ideal pre-treatment technique because it avoids the addition of chemicals to the sample solution and offers continuous operation [29; 30; 31]. However, typical blood cells, such as red blood cells, are significantly smaller (approximately 7 \(\upmu\)m), necessitating the use of larger electric fields for effective lysis.