Taiwanese researchers prototype electricity-free blood typing device tested on 21 samples

Engineers from National Taiwan University have presented a diagnostic platform that combines a microfluidic chip with a hand-powered centrifuge, dubbed hpFuge, to determine blood group and hematocrit without electricity, according to a study published in Biosensors and Bioelectronics sciencedirect.comBiosensors and Bioelectronicssciencedirect.comOpen source ↗. The test requires 3 μL of whole blood and completes the entire diagnostic cycle in 60 seconds.

Hydrodynamics and mechanical filtration

The portable diagnostic setup relies on mechanical rotation instead of an electric drive, driving blood samples through curved microchannels. Optimization of channel length, depth, and curvature radius provides uniform mixing efficiency and flow stability. The design routes fluid toward narrow outlets featuring micro-slits approximately 7.5 μm wide. When target red blood cells encounter matching antibodies, agglutination occurs, forming aggregates that cannot pass through the micro-slit barrier. The channel containing blocked cell clumps reveals the ABO and Rh blood type.

Hematocrit estimation and accuracy validation

Beyond basic identification, the physical length of the trapped agglutinated red blood cell band serves as a direct metric for hematocrit estimation. The researchers established that band length correlates linearly with hematocrit levels across a range of 10% to 60%, achieving a correlation coefficient of R² = 0.99.

Validation on 21 clinical blood samples demonstrated high agreement with hospital automated analyzers, yielding a mean bias of 0.126% and 95% limits of agreement between -0.63% and 0.88% sciencedirect.comBiosensors and Bioelectronicssciencedirect.comOpen source ↗. The instrument-free platform requires no external calibration, displays visual readouts without digital processing units, and functions independently of electrical grids.