A system may comprise a voltage upconverter, a universal serial bus (USB) connector to receive an input voltage from a USB port on a computing device, and a microfluidic diagnostic chip communication link to electrically couple the voltage upconverter to a microfluidic diagnostic chip wherein the voltage upconverter is to convert the input voltage to be received by the USB connector to an output voltage sufficient to drive a pump on the microfluidic diagnostic chip. A diagnostic system may comprise a microfluidic diagnostic chip comprising a pump and a voltage upconverter to receive an input voltage from a universal serial bus (USB) port of a computing device and to convert the input voltage into an output voltage that powers activation of the pump.