A light induced dielectrophoresis (LIDEP) device is configured to perform a sorting process on a liquid including plural first micro-particles and plural second micro-particles. The LIDEP device includes a LIDEP chip and an opaque cartridge. The LIDEP chip includes a first electrode layer, a second electrode layer, a semiconductor layer, and a flow channel layer. The flow channel layer defines a first channel, a second channel and a third channel intersected at a confluence. The first channel is configured to guide the liquid. The flow channel layer further defines a projection region including the confluence. A patterned light source is projected on the projection region, thereby guiding the first micro-particles and the second micro-particles located within the confluence to move toward the second channel and the third channel, respectively. The opaque cartridge covers the LIDEP chip and has an opening. The vertical projection of the opening overlaps the projection region.
