A micropipette-generated vacuum drove a viscosity device requiring 6 microlitres of liquid per test. In one peer-reviewed laboratory study, a phone camera timed samples and water moving through a small channel. Comparing their flow times provided a measure of resistance to flow. The system operates without an electrically powered external pump. Validation covered Newtonian liquids, whose viscosity remains constant, and measurement errors varied across the tested fluids.
Viscosity, a liquid’s resistance to flow, was measured in a laboratory device using 6 µL per test. In the experiments reported by one peer-reviewed study, an adjustable micropipette pulled liquid through a small channel. A phone camera filming at 60 frames per second followed the advancing liquid between two endpoints. The sample’s transit time was compared with water measured under the same conditions.[1]
The channel was made from milled polymethyl methacrylate sheets. Releasing the micropipette plunger creates a vacuum at the outlet that draws liquid through it, without an electrically powered external pump. Settings of 200, 500 and 1000 µL change the air volume generating the pressure difference. The liquid sample remains at the same small volume for each test.[1]
Calculating viscosity from the timing ratio requires matching the channel, temperature, pipette setting and actuation conditions. Tests included glycerol, salt and sucrose solutions and selected pure liquids. The method covers Newtonian liquids, which maintain constant viscosity, and assumes fully developed laminar flow, with fluid layers moving in an orderly pattern.[1]
Each condition was tested five times. Relative variability in repeated flow times ranged from 1.52–9.94 per cent. For liquids assessed at several settings, error metrics at 500 µL ranged from 3.24–11.24 per cent. The lowest-viscosity liquid, n-hexane, moved too quickly under stronger vacuum for reliable timing. Measuring blood or gels, outside the validated liquid group, requires separate testing.[1]
