Removing a medical bandage can cause pain and skin irritation, but for newborns, older adults and critically ill patients, repeated removal of medical adhesives can lead to more serious injuries. Researchers at Pohang University of Science & Technology (POSTECH) have developed a smart adhesive patch designed to remain firmly attached during use while releasing with significantly less force when needed.
The research team was led by Professors Jin-Tae Kim and Seok Kim from POSTECH’s Department of Mechanical Engineering, alongside integrated MS-PhD students Uhyeon Kim and Hyein Jung. Professor Chang-Hee Son of Texas Tech University also contributed to the research, which was conducted in collaboration with Professor John A. Rogers at Northwestern University. The findings were published online in Nature Communications.
The technology addresses a challenge associated with skin-mounted medical devices. Sensors that monitor cardiac activity, respiration and movement need stable contact with the body to collect reliable physiological signals. Conventional adhesives are therefore designed to maximise adhesion, but their strong attachment can make removal difficult and increase the risk of medical adhesive-related skin injury (MARSI).
The new patch uses a shape-memory polymer that changes its surface structure when exposed to mild heat. This allows it to maintain reliable attachment during use and reduce its adhesion when removal is required.
Shape-Memory Technology Enables Controlled Detachment
The researchers designed the adhesive surface with an array of pyramid-shaped structures made from a shape-memory polymer (SMP). These materials can recover a previously programmed shape when exposed to a specific temperature.
In its dormant state, the patch’s pyramidal structures remain flattened. This configuration creates broad contact between the adhesive and the skin, helping the patch maintain a stable attachment during use.
When the patch is gently heated above the polymer’s glass transition temperature, the structures recover their original pyramidal geometry. This transformation reduces the effective contact area between the adhesive and the skin, creating small gaps at the interface and allowing the patch to detach more easily.
Experimental results showed that thermal activation reduced adhesion energy by up to approximately 99%, while the patch maintained stable attachment in its dormant state.
To examine how the adhesive affected the skin during removal, the researchers used three-dimensional digital image correlation (3D-DIC), a technique that allows them to visualise deformation beneath a surface. Their measurements showed that the activated adhesive substantially reduced peeling force and suppressed subsurface skin deformation compared with the dormant state.
These results were observed in both a skin phantom and human skin, providing evidence that the technology can reduce mechanical stress at the skin-adhesive interface.
“This work is meaningful because it controls the mechanical forces at the skin-device interface, rather than simply changing the adhesive material itself,” said Professor Jin-Tae Kim. “By combining stable attachment with low-force removal, the platform offers a practical route toward safer skin-interfaced biomedical devices.”
Flexible Design Supports Wearable Medical Monitoring
The researchers also incorporated a kirigami-inspired structure into the adhesive to improve its ability to conform to curved parts of the body. Kirigami-inspired designs use carefully arranged cuts or patterns to improve flexibility and adaptability.
This modification enhanced the patch’s mechanical conformability around areas such as joints and improved moisture transport through the adhesive layer. These properties could help the patch maintain contact across different body surfaces while supporting comfortable wear.
The team also integrated the adhesive with wireless mechano-acoustic sensing devices. The resulting system demonstrated stable biosignal acquisition while attached to the body, followed by controlled detachment after thermal activation.
The combination of reliable sensing and easier removal could be particularly useful in medical settings where monitoring equipment must be attached and removed repeatedly. Potential applications include neonatal intensive care units, geriatric wards and long-term patient monitoring, where fragile skin may be especially vulnerable to repeated adhesive contact.
Professor Seok Kim highlighted the difference between the new approach and conventional medical adhesives.
“What sets this apart from existing medical adhesive technologies is that it actively switches the adhesive properties by utilizing the microstructure of shape-memory polymers, allowing it to adhere firmly during use and be easily removed when needed.”
Professor Chang-Hee Son also pointed to the technology’s potential beyond medical patches.
“Because this approach enables both reliable adhesion and gentle detachment, it can be extended toward a broader class of technologies in which adhesion needs to be actively controlled on demand.”
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