3D-printed capillary circuits for rapid, low-cost, portable analysis of blood viscosity

Abstract

Blood viscosity is an important rheological property that have a potential for the diagnosis and prognosis of hemorheological alterations; however, conventional viscometers typically rely on costly and sophisticated equipment for device operation and viscosity measurement that limits their use in resource-limited settings. We present a 3D-printed capillary circuit (3D-CC) technology that enables facile analysis of blood viscosity by hand-powered device operation and naked-eye readout. Parallel capillary networks serve as the fluidic comparators that allow direct comparison between the volumetric flow rates of a viscosity standard and a test fluid, while graduated fluidic chambers enable naked-eye readout of the volumetric signals. The 3D-CC platform was first characterized with Newtonian fluids in a relatively wide range of viscosities (4.8–71.2 cP) by simple operation, pulling and pushing the plunger of a syringe. The practical utility of the 3D-CC was then demonstrated by rapid, low-cost, portable analysis of whole blood under controlled shear-rate conditions (48.5–482.1 s−1). The proposed platform provides cost-effectiveness and simplicity of operation compared with conventional viscometers, making it suited for its widespread use in field-based applications.