USB powered Cyto Centrifuge

thingiverse

A USB-powered centrifuge can be constructed for under $10 using a small DC motor (1.5-6V, 4000 RPM) and a DC motor speed controller kit. The centrifuge features a 40mm radius and spins at up to 4000 RPM on a 4.5V/100mA USB port, providing a centrifugal force of 500 gravities. PCR tubes weighing approximately 0.5g can be spun in the centrifuge, achieving a weight equivalent to half a 17oz water bottle at 500 gravities. A small piece of reflective tape on the top side of the right rotor arm is used by the tachometer to measure RPM, which exceeds 4k RPM. The motor's capacitor provides enough energy for smooth spinning and minimal noise in the circuit. For a safe enclosure, consider using a metal coffee mug. Instructions for assembly are provided, including printing the necessary parts, finding a suitable DC motor, and wiring the speed controller. An optional DPDT slide switch can be added for motor direction reversal.