Low-cost digital microfluidic approach on thin and pliable polymer films

A digital microfluidic device fabricated with a thin and pliable polyester film is reported with control by a custom-made battery-powered high voltage amplification circuit. Droplet movement on the tilt or curved surface was achieved. A low-cost approach for the fabrication of digital microfluidic device was used: the electrodes on the digital microfluidic device were fabricated with conductive carbon ink screen-printed on a polyester substrate, a layer of thin polyethylene film was used to seal and insulate the electrodes, and a layer of water repellent was coated on the surface of polyethylene film to enhance the hydrophobicity. The device is transparent and pliable, with a total thickness of approximately 70 μm. The controlled droplet movement on the curved polymer surface based on electrowetting was achieved with the compact voltage amplification circuit and the corresponding control algorithm. The fabrication for the proposed digital microfluidic device is low-cost and without sophisticated microfabrication instrumentation. Furthermore, the system is portable and may have widespread point-of-care in biological and medical applications.