Biofluidic chips are widely utilized in medical testing for polymerase chain reaction, or PCR, tests, which use lab-on-a-chip devices to diagnose various diseases or genetic changes. Although originally invented in the 1980s and widely used in the scientific community, PCR tests gained prominence among the wider public during the COVID-19 pandemic. They are held as the “gold standard” for accuracy among diagnostic tools.

However, PCR tests and other lab-on-a-chip devices are accurate only if the chips are built correctly, undamaged, properly used and have not been tampered with. Lab-on-a-chip tests must be processed and handled by multiple parties before reaching their destinations in medical facilities. This process presents the risks of chips being damaged or tampered with by malicious entities in the supply chain for financial gain.

The effects of inaccurate results from lab-on-a-chip tests can have grave consequences. For example, a false negative result can cause accidental spread of viral diseases or fail to alert scientists of a medication’s side effects before its use on humans.

To ensure accuracy and reliability of lab-on-a-chip tests, Krishnendu Chakrabarty, Fulton Professor of Microelectronics in the Ira A. Fulton Schools of Engineering at Arizona State University, and Ramesh Karri, a professor of electrical and computer engineering at New York University’s Tandon School of Engineering, collaborated with researchers led by New York University Abu Dhabi postdoctoral associate Navajit Singh Baban on a National Science Foundation-funded project to develop two types of watermarks activated when a legitimate and properly functioning test is used. One watermark uses a dye only visible under ultraviolet light, and the other causes a reaction when force is applied.

The science journal Lab on a Chip published the team’s research in an associated paper, “Material-level countermeasures for securing microfluidic biochips,” in August 2023.

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