This paper reports an innovative approach for the manipulation of micro-particles utilizing optically-induced dielectrophoresis (ODEP), which was generated by a flexible polymer-based substrate for biomedical applications. The ODEP platform fabricated on a thin-film polymer-based substrate has been reported as a promising technique for particle/cell manipulation. Without using sophisticate and high-temperature thin-film process, the entire fabrication process can be performed at low-temperature and completed in a shorter period of time when compared with the fabrication process of amorphous silicon. In this study, we fabricated the ODEP device on a flexible substrate, which may further extend its practical applications. In addition, the rapid separation of micro-particles can be realized with the incorporation of gravity effect utilizing the arch-shaped flexible substrate. More importantly, the fabrication process was compatible with the roll-to-roll process such that large-area, flexible polymer substrates can be adopted for further applications such as concentration, transportation and separation of micro-particles/cells. The novel fabrication process using the flexible substrate may provide a promising and cost-effective approach for mass-production of the ODEP devices.