Chinese scientists are taking personal health monitoring to the next level by developing a new type of e-skin with enhanced biomechanical and biochemical sensing capabilities.

For the first time, these wearable devices composed of biocompatible composites are activated by sweat instead of being impeded by it.

“For healthy people, wearable monitoring has long been limited by two overlapping issues: motion artefacts and sweat. Our single material solved both issues. A single comfortable patch can continuously track cardiac signals and metabolites during daily activities,” explains Xiu Liang, professor at the School of Materials Science and Engineering, Qilu University of Technology.

“For clinicians, our work has provided an easy-to-use tool to convert sweat into clinical data, potentially enabling needle-free early detection of gout, arrhythmia, or even early Parkinson’s disease,” she adds.

Despite the current era of technological advances, wearable personal health monitoring sensors suffer from poor skin conformity, insensitivity, and signal transmission problems.

Improving biocompatibility and addressing skin conformity issues are top areas of focus for researchers in this field. Up to the challenge are Xiu Liang and colleagues from universities across China, whose novel design enables both real-time physiological and biochemical monitoring of clinical biomarkers.

Don’t sweat it 

It is said that “necessity is the mother of invention” and this was the case with the researchers who were forced to think outside the box because of technical issues with earlier designs. These earlier designs were plagued with signal problems because the e-skin moved and slid when in contact with wet, sweaty skin. After numerous attempts to make the device tighter, the team realised they were addressing the wrong root cause.

“Once we stopped seeing sweat as a nuisance and started treating it as a resource, the solution seemed clear,” explains Liang.

Instead of fighting against sweat, they changed the e-skin material to a composition that leveraged sweat to enhance device adhesion to the skin and improve signal. The material uses a composite of silk fibroin and silver nanowires.

“Think of it as a smart bandage, thinner than a human hair, with dual functions,” explains Liang.

“The workflow is straightforward. You sweat, the silk absorbs, the nanowires simultaneously record the cardiac activities and identify your metabolites, sending data to a mobile phone. The sweat never has to leave the patch,” Liang adds.

In addition, the silver top layer forms an antimicrobial barrier, reducing bacterial growth of S. aureus and E. coli by about 50%. Integrated into this e-skin are plasmonic sensors that detect biomarkers by their oscillations and effects on metal surfaces. More specifically, the team use surface-enhanced Raman spectroscopy (SERS) plasmonic sensors. This boosts detection capabilities, enabling measurements at ultralow concentrations of biomarkers.

The study challenges the status quo, proving, as Prof. Xiu Liang says, that water and sensors do not have to be adversaries.

“In wearable sensing, hydration is no longer a failure mode — it becomes the signal.”

Liang says their design and approach are novel in several ways. They are the first researchers to pack electrical and chemical sensing capabilities into one single layer. Furthermore, their hydration-triggered design solves two problems, because the absorption of sweat also aids adhesion of the device to wet skin.

Liang says that, unlike most wearable materials research, they did not take a trial-and-error approach. Instead, they performed simulations to predict the amount of water silk fibroin would absorb. To their surprise, the predicted value was unusually close to their experimental value. The team say this gave them confidence they were on target before developing devices.

Translation into clinical practice

The researchers have developed a device that harnesses sweat, but what can sweat tell us about how the body is functioning?

“Sweat is full of uric acid, urea, lactate, even biomarkers for neurodegenerative diseases. It offers a rich chemical record of the body status, yet this valuable signal is largely discarded in current clinical practice,” explains Liang.

This is just the beginning, and further optimization is needed to ensure long-term usability of the e-skin. After that, the team say focus will turn to manufacturing scalability. With low-cost raw materials readily available, the main anticipated issue is batch to batch variability during production. They also acknowledge that multi-centre studies are needed to understand any variability in device measurements across diets, ethnicities, and climates.

Liang says another hurdle will be obtaining regulatory approval for the device, especially if it is one day offered as a replacement for blood testing.

Despite these challenges, the team are hopeful moving forward and future studies plan to measure α-synuclein, a biomarker of neurodegenerative diseases as Liang explains: “For the 5-10 year horizon, we aim to address the key question raised in our paper’s outlook: can we screen for Parkinson’s disease years before symptoms emerge, by tracking α-synuclein in sweat? Sweat α-synuclein is already a well-studied biomarker. If continuous and non-invasive detection can be achieved, we hope to identify at-risk patients five to ten years earlier than current methods.”

With applicationsfor point-of-care diagnostics and the possibility of integrating other functionalities, Liang believes it’s possible their device could one day be distributed worldwide.

“We envision this future scenario: ten years from now, a rural village doctor carries a box of these patches. One is applied to an elderly resident living alone. The next day the township clinic sees that elderly’s ECG and uric-acid curve from the night before, and the doctor tells the family to use less high-purine foods such as organ meats, seafood, rich broths, and arrange a follow-up visit. Low materials cost, scalable production and no bulky equipment required:  that is, I think, one of the tangible ways for materials science to advance health equity.”

Reference: Z. Mu et al., A Hydration-Triggered Electronic Skin for Integrated Biomechanical and Non-Invasive Plasmonic Biochemical Sensing, Advanced Functional Materials (2026), DOI: 10.1002/adfm.77776

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