2.2. Rotor and optical systems for the centrifugal microfluidic disc
The rotor system and its operating software were purchased from Hanra Precision Engineering (Incheon, Korea) and modified by our lab. The system was composed of an 808 nm laser diode (TTG50TEC, Laser Solution Korea, Ansan, Korea) for the ferrowax microvalve operation, a camera (BFS-U3-16S2C-CS, FLIR Systems, Inc., Boston, MA, USA), and stroboscopic lights (BUB 0641 (G), PerkinElmer, Inc., Waltham, MA, USA) for the imaging of the disc. The laser module was automatically controlled by a one-dimensional step motor (EzM-42S-A, Fastech, Bucheon, Korea), and a polar coordinate system was used to precisely control the laser irradiation position on the disc based on the rotational angle and radial distance from the edge. A rotary servo motor (SGM7J-02A, Yaskawa Electric Corp., Kitakyushu, Japan) was used to rotate the disc. Home and trigger sensors (EE-SX671A, Omron Corp., Kyoto, Japan) were used to accurately adjust the rotational position. A detailed illustration of the rotor system is provided in Figure S2.