Dangerous biomarkers in human sweat detected by portable sensor
A portable chip that can encapsulate and analyse biomarkers in a person’s sweat has been developed by EPFL researchers in collaboration with startup Xsensio.
The low-power system is able to fit on a chip measuring under 1cm² and can be placed directly onto a person’s skin or integrated into a bracelet.
It analyses specific biomarkers contained in sweat to give valuable insight into the wearer’s health.
It can determine the sodium and potassium concentrations in the person’s sweat, for example, and measure their body temperature and pH. This data can then be sent directly to a smartphone for further analysis.
The system uses capillary action to ‘pump’ miniscule amounts of sweat into the heart of the chip, where it is analysed.
The chip contains four silicon sensors that are only around 20 nanometres thick, making them extremely sensitive.
Each sensor is coated with a different material so that they can each detect different biomarkers.
“Our platform is truly modular. By depositing different biochemical layers on each of the miniature sensors, we can measure a host of variables ranging from electrolytes and metabolites to tiny molecules and proteins. That gives users personalised real-time data,” said Esmeralda Megally, CEO of Xsensio.
The system includes two fluidic layers that sit between the chip and the user’s skin. These layers ‘pump’ up sweat from the skin and carry it to the sensors.
As this pump relies entirely on capillary action, it runs continuously and without electricity.
“Ours is the only device out there that includes such a system on a chip,” said Professor Adrian Ionescu, lead researcher. “Even today’s most advanced devices use sensors that are 10,000 times bigger than ours and need a larger volume of sweat to be able to effectively analyse biomarkers.”
Such extreme miniaturisation was made possible thanks to sensor technology developed at the Nanolab – the same technology that’s used in computer microprocessors. Xsensio, which is coming up with the marketing strategy for the system, contributed two innovations: the nanofluid interface with users’ skin and the thin biochemical layers that enable the sensors to detect specific biomarkers.
Now the project team is working on incorporating the system into a bracelet or other wearable device so that it can be launched on the market.
The data that the system collects can give important insight into both a user’s health and wellness. For example, chlorine levels can give an early indication of cystic fibrosis and ion levels can signal dehydration. Measurements of other biomarkers can flag symptoms of fatigue and stress and eventually even risk factors for other illnesses.
Last year, Harvard University researchers demonstrated an automated manufacturing process for creating 3D-printed organs that can be used to run personalised medical diagnostics on patients.