A prototype fitness sensor, developed using the new MXene, hydrogel compound, was able to track the movement of the muscles by generating distinct electrical resistance patterns as mechanical stress augmented.
As described in Phys.org, such patterns, in turn, changed rapidly when the sensor was exposed to more ions in the form of basic or acidic solutions.
MXenes, also known as ultrathin nanomaterials, is developed to make it easier to observe and follow a person's wellbeing by analyzing their perspiration.
While they share the exact two-dimensional nature as graphene, MXenes comprise nontoxic metals like titanium, in combination with carbon and nitrogen atoms.
MXene Inserts Loaded with Suitable Enzymes Used
MXenes, which have naturally high conductivity, not to mention surface chargers, are enticing candidates for biosensors with the ability to detect tiny changes to chemical concentrations.
It was two years ago when the group of Husam Alshareef developed an MXene, encased in a wearable armband sensor.
The device, designed to have a modular design that utilized MXene inserts loaded with suitable enzymes, could absorb sweat and detect numerous "analytes" in human perspiration, including glucose and lactic acid.
Alshareef, together with his colleagues, in alliance with the research team of Sahika Inal, recently attempted to combine MXene sheets with hydrogels. These water-filled polymers are compatible with human tissue since they can stretch.
Interestingly, in their study, published in Small Methods, the team discovered that high mobile ion levels in the hydrogel generated strong sensitivity to the mechanical strain during physical exercise.
Device Used to Associate pH Changes in Sweat
At first, the MXene sheets are randomly concentrated within the hydrogel, although once pressure is applied, the ultrathin sheets turn more horizontally oriented, Alshareef explained.
Since MXenes have a high negative charge concentration on their surface, horizontal arrangement intensely impacts ion movements within the hydrogel, and therefore, different levels of pressure change can be measured.
This prompted the KAUST team to discover that their newly developed device could be utilized to associate pH changes in perspiration with acid buildups which are fatigue-inducing, specifically in muscle cells.
According to former KAUST postdoc and the study's lead author Kang Lee, as one exercise and his muscle gets tired, the sensor sees the new chemical environment, not to mention generating different electrical resistance against stress curves.
MXene-Based Fitness Sensor
Lee also explained, through the comparison of such curves to reference curves for a given sensor, the pH of the sweat can be determined and how fatigued such a muscle is.
Using Bluetooth technology, connecting to digital devices nearby, the MXene-based fitness sensor may prove valuable to athletes searching for real-time performance measurements the moment technology has been optimized.
According to Alshareef, the most serious challenge here is the long-term stability of the fitness sensor, and thus, they are looking at modifying compositions and designs in future studies.
Related information about MXenes is shown on Graphene Flagship's YouTube video below:
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