Researchers have developed a portable, electricity-free device that uses a hand-cranked centrifuge to perform blood typing and hematocrit testing.

A team led by Professor Chien-Fu Chen at National Taiwan University has created a small plastic chip that identifies blood type and hematocrit levels without electricity. The device uses a hand-cranked centrifuge to process a 3-microliter blood sample from a finger prick. The results are available in approximately one minute, offering a potential alternative for ambulances, disaster zones, and remote clinics where standard laboratory equipment is unavailable.

How the device functions

The device features winding channels preloaded with reagents for A, B, and Rh blood groups. When the centrifuge is cranked, blood is pushed through these channels. If the blood type matches, red blood cells clump together and are trapped by a micro-slit roughly one-tenth the width of a human hair, forming a visible red band. A printed scale on the chip allows users to read the blood type and measure the length of the band to determine the hematocrit, which indicates the proportion of red blood cells.

Testing and performance

In a study published in Biosensors and Bioelectronics, researchers tested the device on 21 hospital patient samples. The results were consistent with standard hospital analyzers, and the readings remained stable regardless of the speed at which the crank was turned. Professor Chen stated that the goal is to provide first responders with a tool that requires no specialized training or power source.