Smart Medical Adhesive Patch Uses Heat to Enable Gentle Removal

Strong adhesives keep sensors securely attached to record cardiac, respiratory, and motion signals, but their application and removal can cause irritation, epidermal damage, and skin stripping. To balance reliable attachment with gentler removal, researchers have developed a smart adhesive patch designed to remain secure during use and release gently when needed.

The medical adhesive patch was developed by a Department of Mechanical Engineering team at POSTECH with collaborators from Texas Tech University and Northwestern University. The work focuses on controlling mechanical forces at the skin-device interface rather than only changing adhesive chemistry. The findings were published online in Nature Communications.

The patch uses a shape memory polymer (SMP), which can recover a programmed shape when exposed to a specific temperature. Its surface contains an array of pyramidal structures that remain flattened in the dormant state. This flattened configuration allows broad contact with the skin and supports stable attachment during monitoring.

When the patch is mildly heated above the glass transition temperature, the pyramids recover their original geometry. This change reduces the effective contact area between the skin and adhesive. It also creates interfacial gaps that allow the patch to detach with substantially lower force.

Experimental testing showed that thermal activation reduced adhesion energy by up to approximately 99% while maintaining stable attachment during use. The team used three-dimensional digital image correlation (3D-DIC) to visualize deformation beneath the skin surface during detachment. Compared with the dormant state, the activated SMP adhesive reduced peel force and suppressed subsurface skin deformation in both a skin phantom and human skin.

The researchers also added a kirigami-inspired structure to improve wearability on curved body regions, including joints. This design enhanced mechanical conformability and improved moisture transport through the adhesive layer. The adhesive was integrated with wireless mechano-acoustic sensing devices and demonstrated stable biosignal acquisition during normal attachment, followed by controlled detachment after thermal activation.

“This work is meaningful because it controls the mechanical forces at the skin-device interface, rather than simply changing the adhesive material itself. By combining stable attachment with low-force removal, the platform offers a practical route toward safer skin-interfaced biomedical devices,” said Professor Jin-Tae Kim.

“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,” stated Professor Seok Kim.

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