New spinning microfluidic device inspired by a spinning toy

Often, patients with urinary tract infections (UTI) are treated with antibiotics. Approximately 59% of patients were over-or under-prescribed antibiotics for UTI while waiting for conventional test results.

In a new study, scientists from UNIST have introduced a custom-made fidget spinner- a spinning microfluidic device that can detect UTI within an hour. Unlike conventional lab tests, this fidget spinner toy-inspired pinning microfluidic device works much faster and can help improve patient care, especially in low-resource settings. What’s more, it is inexpensive, portable, and accurate.

Microfluidic spinning generates a centrifugal force that pushes the urine sample outwards to spread over a filtration membrane. As the sample drains, the bacteria particles reside on the top.

There is a drainage chamber that lies beneath the filtration membrane—this buffer solution-filled chamber allows uniform filtration of the urine.

When the centrifugal force is combined with FAST technology (fluid-assisted separation technology), it filters and enriches bacteria in the urine sample colorwise. This makes it easy to detect the UTI by the naked eye—a larger infection results in a darker orange or red color.

UNIST biomedical engineer Yoon-Kyoung Cho said, “This allowed for maximized bacterial cell enrichment efficiency while minimizing the force needed for the filtration. One or two spins were enough to filter a one-milliliter sample, despite a large variation in the spin speed generated by people with different hand power.”

The device’s effectiveness was tested by taking urine samples from 39 patients suspected of having a urinary tract infection in Tiruchirappalli, India. The machine offered a comparable result on-site in only 50 minutes. Also, it tested the bacteria’s susceptibility to two different antibiotics for UTI within just two hours. This will help physicians determine which one would be more effective for treating the patient.

Professor Cho says, “I hope our rapid on-site test can help more patients get the most effective treatment, especially since UTIs are one of the most common infections in the world.”

Journal Reference:

1. Michael, I., Kim, D., Gulenko, O. et al. A fidget spinner for the point-of-care diagnosis of urinary tract infection. Nat Biomed Eng 4, 591–600 (2020). DOI: 10.1038/s41551-020-0557-2

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