Rotational separation of non-spherical bioparticles using I-shaped pillar arrays in a microfluidic device.

Most bioparticles, such as red blood cells and bacteria, are non-spherical in shape. However, conventional microfluidic separation devices are designed for spherical particles. This poses a challenge in designing a separation device for non-spherical bioparticles, as the smallest dimension of the bioparticle has to be considered, which increases fabrication challenges and decreases the throughput. If current methods do not take into account the shape of non-spherical bioparticles, the separation will be inefficient. Here, to address this challenge, we present a novel technique for the separation of red blood cells as a non-spherical bioparticle, using a new I-shaped pillar arrays design. It takes the shape into account and induces rotational movements, allowing us to leverage on the largest dimension, which increases its separation size. This technique has been used for 100% separation of red blood cells from blood samples in a focused stream, outperforming the conventional pillar array designs.