Handheld diagnostic device could increase access to testing in future pandemics

Inspired by the challenges that many people faced when trying to access Covid-19 testing, scientists at UCLA have developed a device that serves as an all-in-one lab kit for fast and efficient diagnostics. 

Using swarms of pinhead-sized magnets inside a handheld device, the automated tests can be easily manufactured, deployed and performed at a doctor’s office, health clinic or at mass testing sites in airports and schools at the onset of any major infectious disease.

The technology, outlined in the journal Nature, could help the authorities better prepare for future pandemics by decentralising testing and maximising the use of resources.

The researchers tested their device in a clinical study with test samples from individuals who experienced Covid-19 symptoms. More than 100 test results using the lab kit were compared to the same samples tested for Covid-19 using polymerase chain reaction (PCR)-based molecular diagnostics performed as part of UCLA Health’s routine clinical care.

“Our handheld lab technology could help overcome some of the barriers of scarcity and access to tests, especially early in a pandemic, when it is most crucial to control disease spread,” said associate professor Sam Emaminejad, a co-author of the study. 

“Bbeyond its potential to address issues of short supplies and high demand, it could be broadly adapted to test for many types of diseases in field and with lab-grade quality.”

Using a circuit board that controls a set of movable, 1mm-sized magnetic discs known as ‘ferrobots’ to transport samples through the diagnostic workflow of a nucleic acid amplification test (NAAT), the researchers’ ultra-sensitive lab kit was able to detect the presence of genetic material from the SARS-CoV-2 virus successfully.

The steps to separate, sort, mix and amplify testing samples were all automated and performed at a miniaturised level inside the kit.

“This platform’s compact design and automated handling of samples enable easy implementations of pooled testing where you can test dozens of patient samples at the same time, all with the same materials it currently takes to test just one patient,” said UCLA Samueli School of Engineering professor Dino Di Carlo. 

“For example, you could test students in an entire college residence hall with just a few dozen test kits.”

By designing the kit for pooled testing, the system requires much lower amounts of reagent chemicals than those needed for testing the samples individually. Moreover, thanks to the technology’s assay miniaturisation and pooled-testing capabilities, the chemical reagent costs could be reduced by 10 to 300 times.

Aside from being able to test for several diseases simultaneously, the platform also offers precision and robust automation. For example, in a pooled-testing with 16 samples, more than 300 lab operations, including mixing and sorting, were automated by the ferrobots – more than 3,000 individual movements, or actuations.

In their reliability studies, the researchers showed that the ferrobots could perform more than eight million actuations without mistakes.