3-D Printed Integrated and Automated Electro-Microfluidic Viscometer for Biochemical Applications

Viscometers are broadly employed in a wide range of sensing and monitoring applications, such as biochemical optimization, biomedical diagnostics, pharmaceuticals, and various adulteration detections. When realizing them in a microfluidic environment, the viscometers can potentially be used in an automated and robust point-of-care setting. Even after so much evolution, one of the constant challenges faced in the development of microfluidic devices is to choose the best fabrication scheme, particularly, in terms of a simplified process, cost, and time. Here, we present a 3-D-printed electro-microfluidic viscometer (EMV) which mimics the conventional Ostwald viscometer. The EMV measures the reference fluid viscosity, under laminar flow, by automatically evaluating the travel time of the sample fluid vis-a-vis to that of a reference fluid. The EMV, consisting of a microchannel and four equidistance electrodes, was fabricated using a simple desktop fused deposition modelling 3-D printer in a single step. The complete platform, comprising of the microfluidic device, pumping subsystem, data acquisition subsystem, and signal processing subsystems, has been integrated and automated to determine the viscosity.