Design of a precision and programmable current source power supply for efficient microfluidic mixing process

Microfluidic systems are essential for biomedical diagnostics, chemical synthesis, and environmental monitoring. However, achieving efficient mixing in microchannels is challenging due to the laminar flow. Traditional passive micromixing methods often lack control and efficiency. This study introduces an electromagnetic micromixer system to enhance mixing efficiency. The system employs two electromagnets on either side of the microchannel, where alternating magnetic fields generate lateral forces on magnetic particles, driving them toward higher magnetic field density. A microcontroller-based control unit manages the system, modulating current waveform parameters using DACs, Op-Amps, and MOSFETs. The program automatically adjusts the setup's current value to ensure consistent performance by adding a coefficient when the MOSFETs' temperature exceeds normal. Experimental validation demonstrated high accuracy in current control and consistent pulse width generation. The system can configure currents ranging from 1 mA to 15,000 mA, pulse widths from 5 µs to 65 ms, and delays from 5 µs to 65 ms. This micromixer shows excellent potential for precise mixing in microfluidic applications.