This New Paper-Based Wearable Sensor Could Save Patients Lives

Researchers at Purdue University have managed to create wearable sensor "smart sticker" that can be used to monitor heart patients' health from the comfort of their own homes. 

These new "smart stickers" are primarily made from cellulose which means they are very cheap to make and biocompatible and breathable for the wearer.

According to Ramses Martinez, Purdue University Assistant Professor of Industrial Engineering and Biomedical Engineering, the University has “For the first time, we have created wearable electronic devices that someone can easily attach to their skin and are made out of paper to lower the cost of personalized medicine,”

What will these "smart stickers" be used for?

The plan is to use them to monitor the physical activity of the patient and alert a wearer about possible problems in real-time. 

Other health professionals can also benefit from the technology for other medical surveillance. Athletes could also use them to monitor and log their performance during exercise and training including things like swimming.

Since they are biocompatible they could also be implanted onto the internal organs of patients for other medical surveillance like sleep pattern monitoring.

They will be cheap and quick to make

More traditional production methods and materials for epidermal electronics tend to be a complex process and expensive to complete. This often precludes them from being used for single-use applications.

Purdue's new "smart stickers" in contrast have a very simple design and constituent materials cost around 5 US cents (just over 3.5 UK pence)  to make. They can also be mass-produced using printing and other manufacturing processes similar to those used to print books at high speed.

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Their production includes, according to their ACS study, "the fabrication of epidermal, paper-based electronic devices (EPEDs) for wearable and implantable applications by combining the spray-based deposition of silanizing agents, highly conductive nanoparticles, and encapsulating polymers with laser micromachining".

“The low cost of these wearable devices and their compatibility with large-scale manufacturing techniques will enable the quick adoption of these new fully disposable, wearable sensors in a variety of healthcare applications requiring single-use diagnostic systems,” Martinez said.

How does it not get wet and fall off?

The paper "smart stickers" have a serpentine shape patterning to them that allows them to be very thin. They can also stretch and contract with human skin and are, more or less, imperceptible to the wearer.

Being cellulose based they are potentially very susceptible to getting wet. Since humans tend to sweat, have showers etc they have had to be engineered to be hydrophobic.

As a solution, researchers developed a special molecular coating for them that has been formulated to repel water, oil, dust, and microbes. 

This study was originally published in ACS Advanced Materials and Interfaces.